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AIBU?

Share your dilemmas and get honest opinions from other Mumsnetters.

To think "half your age plus seven" is a massive pile of nonsense?

370 replies

TransportNerd · 01/07/2026 08:07

Mumsnet seems to take a very dim view of age gap relationships, far more so than I think the general population does. I've seen plenty of age gap relationships work just fine.

Every single time they're discussed here, though, someone wheels out the "rule" that you shouldn't date someone younger than half your age plus seven years.

People treat it like it's absolutely set in stone, and that breaking this "rule" is some sort of disgusting taboo. I've even seen someone argue it should be enshrined in law, with penalties for those who break it.

Personally, I've always thought it was complete nonsense. It was simply something in a French novel in the early 1900s. It doesn't really take anything important into account, and ignores the principle that consenting adults can do what they like.

Quite apart from anything else, why is it plus seven? Why not five, eight or ten? I'm sure it's only seven because that's a number that's had mystic significance since ancient times. Not a good basis for making laws!

Anyway:

YABU - yes, it's a rule and shouldn't be broken
YANBU - it's a big pile of nonsense and doesn't mean anything

OP posts:
PenelopeJoanSterling · 05/07/2026 22:51

IcedPurple · 05/07/2026 22:47

What kind of 30 year old wants to date a teenager?

if they connected on hobbies, similar taste in films music enjoys different locations, if the 18 has worldly experience or has various hobbies they can discusss, not all 18yr olds are glued to love island etc.

after all medievel times, 18+ were leading armies, rasing families etc so if they could do that then then what happened with society did we suddenly say oh you have to wait till your 30 had plenty of failed relationships been through the ringer then you can have your age gap relationship ?

coocoocachoop · 05/07/2026 22:49

PenelopeJoanSterling · 05/07/2026 22:45

but why if they care about each other and if its what the 18 yr old wanted ? as someone said upthread they could be in a same age relationship and get disrespected etc so its odd why socety judges first rather than asks does the older one treat them with respect and makes them happy ?

surley thats what should matter more as long as they are 18+ then surley a happy and stable relationship is better even if its an age gap one ?

Because the 30 year should know better. Because the 30 year should be able to recognise how immature an 18 year old is, how lacking in experience they are, how they would hold them back. If the 30 year old genuinely had feelings for the 18 year old they would let them go. But they don’t, because they’re selfish and usually have nefarious reasons as to why somebody so young suits them.

IcedPurple · 05/07/2026 22:47

PenelopeJoanSterling · 05/07/2026 22:45

but why if they care about each other and if its what the 18 yr old wanted ? as someone said upthread they could be in a same age relationship and get disrespected etc so its odd why socety judges first rather than asks does the older one treat them with respect and makes them happy ?

surley thats what should matter more as long as they are 18+ then surley a happy and stable relationship is better even if its an age gap one ?

What kind of 30 year old wants to date a teenager?

PenelopeJoanSterling · 05/07/2026 22:45

kkloo · 05/07/2026 22:39

No judgement towards the 18 year old, all judgement towards the 30 year old.

but why if they care about each other and if its what the 18 yr old wanted ? as someone said upthread they could be in a same age relationship and get disrespected etc so its odd why socety judges first rather than asks does the older one treat them with respect and makes them happy ?

surley thats what should matter more as long as they are 18+ then surley a happy and stable relationship is better even if its an age gap one ?

kkloo · 05/07/2026 22:39

PenelopeJoanSterling · 05/07/2026 22:03

but then what if its the younger one that falls in love with the older one ?

No judgement towards the 18 year old, all judgement towards the 30 year old.

PenelopeJoanSterling · 05/07/2026 22:03

Tableforjoan · 05/07/2026 18:40

I think if you have children you shouldn’t date around or below your child’s age. That’s creepy.

30 year old dating a 18 year old creepy.

40 and 60 year old cool beans.

I also think it’s weird when parents have children around the same ages as their grandchildren too.

but then what if its the younger one that falls in love with the older one ?

Grendel7 · 05/07/2026 20:09

2dogsandabudgie · 01/07/2026 08:22

I tend to ignore age gaps. If it was my adult children I would rather there was a 20 year age gap and they were happy and being treated with respect than with someone their own age who was abusive or a drug addict etc.

Well said!! Thank you for being sensible and adult about this clearly contentious issue in some peoples opinions

kkloo · 05/07/2026 20:09

Grendel7 · 05/07/2026 20:06

Who says? It surely depends on the individuals? Glad your'e not my mum.

In my kids school 16 and 13 would not have been appropriate, they would have said the 16 year old was a pedo, they are very against age gap relationships like that, and they wouldn't be a woke bunch or the type who are permanently offended, the exact opposite really but very against these age gaps.

Grendel7 · 05/07/2026 20:06

Ohcrap082024 · 01/07/2026 08:18

As the mother of teens, I think it’s a pretty good rule of thumb. So when my dd was telling me about a 16 year old dating a 13 year old, we used the rule to explain why that’s not appropriate.

16 and 15 is fine. 16 and 13 is not.

Edited

Who says? It surely depends on the individuals? Glad your'e not my mum.

OneFineDay22 · 05/07/2026 19:46

IcedPurple · 05/07/2026 18:46

Even if you don't have children, a generational age gap is creepy.

I agree. Old enough to be someone’s parent, then it’s weird. And of course I wouldn’t stop two people with an age gap like that from being together, but I would absolutely think it was weird. And obviously so would the majority of people.

IcedPurple · 05/07/2026 18:46

Tableforjoan · 05/07/2026 18:40

I think if you have children you shouldn’t date around or below your child’s age. That’s creepy.

30 year old dating a 18 year old creepy.

40 and 60 year old cool beans.

I also think it’s weird when parents have children around the same ages as their grandchildren too.

Even if you don't have children, a generational age gap is creepy.

Tableforjoan · 05/07/2026 18:40

I think if you have children you shouldn’t date around or below your child’s age. That’s creepy.

30 year old dating a 18 year old creepy.

40 and 60 year old cool beans.

I also think it’s weird when parents have children around the same ages as their grandchildren too.

kkloo · 05/07/2026 18:36

Reba125 · 05/07/2026 15:36

Think also we are missing the point we are dealing will consenting ADULTS here …. I do not have the right to tell other consenting adult couples who they can love and marry ….Just as I would not take kindly to anyone thinking they have a right to tell me which other adult I can love and marry purely down to age ….

I don't care if you wouldn't take kindly to it, if you decided to love and marry an 18 year old I'd think you were disgusting and be very concerned about the very young adult you were involved with.

You have the right to do it, you have absolutely zero control about what people think about it.

coocoocachoop · 05/07/2026 16:19

Reba125 · 05/07/2026 15:36

Think also we are missing the point we are dealing will consenting ADULTS here …. I do not have the right to tell other consenting adult couples who they can love and marry ….Just as I would not take kindly to anyone thinking they have a right to tell me which other adult I can love and marry purely down to age ….

No one (barring the one poster calling for a law change lol) here is saying we have the right to stop it, but we have the right to an opinion on it. It’s something I have quite strong opinions on.

Reba125 · 05/07/2026 15:36

Think also we are missing the point we are dealing will consenting ADULTS here …. I do not have the right to tell other consenting adult couples who they can love and marry ….Just as I would not take kindly to anyone thinking they have a right to tell me which other adult I can love and marry purely down to age ….

IcedPurple · 05/07/2026 12:16

WillThingsEverBeFergaliciousAgain · 05/07/2026 12:10

In all fairness, controlling narcissists are far more likely to go for vulnerable people they can control, so are more likely to be in age gap relationships, with them being the older one.

Exactly.

We can all think of huge age gap relationships with 'work' and same age relationships which don't. But generally speaking, I would bet that men (and yes it's pretty much always men) who seek out much younger partners have a higher chance of being a controlling type.

Statistically, these relationships also have a high failure rate.

WillThingsEverBeFergaliciousAgain · 05/07/2026 12:10

Reba125 · 05/07/2026 11:59

So I put it this way … my mum was 25 when she married my dad who was 46 …they celebrated their 50th wedding anniversary before dad died ….they had their ups and downs as everyone does sometimes more downs than ups but it worked out okay in the end … then we have my niece going through a very traumatic divorce involving police .. both are the same age were in the same class at school..,so it seems he was a controlling narcissist… so age does not matter…. it’s the character that counts more than age…

In all fairness, controlling narcissists are far more likely to go for vulnerable people they can control, so are more likely to be in age gap relationships, with them being the older one.

Reba125 · 05/07/2026 11:59

So I put it this way … my mum was 25 when she married my dad who was 46 …they celebrated their 50th wedding anniversary before dad died ….they had their ups and downs as everyone does sometimes more downs than ups but it worked out okay in the end … then we have my niece going through a very traumatic divorce involving police .. both are the same age were in the same class at school..,so it seems he was a controlling narcissist… so age does not matter…. it’s the character that counts more than age…

OneFineDay22 · 05/07/2026 11:43

coocoocachoop · 05/07/2026 09:44

So that’s one person, not “mumsnet”. I just find it odd you’ve started a thread about a formula that is not widely spouted, about a topic that is not directly impacting you in your life because of a handful of people on the internet who have a different opinion to you. I mean I know that’s MN, discussion forum etc etc, but people usually have some skin in the game in the thread they’ve started.

Yes just to discuss all these hypothetical much older people “of both sexes” that genuinely connected with a “consenting” adult less than half their age, who unfairly get tarred with the same brush as the actual creeps by people who don’t know them (I’m sure they’ll live).

coocoocachoop · 05/07/2026 09:44

TransportNerd · 05/07/2026 08:06

Well, the person I was talking about who has repeatedly and seriously argued it should be made law has just predictably reappeared to do so again.

So that’s one person, not “mumsnet”. I just find it odd you’ve started a thread about a formula that is not widely spouted, about a topic that is not directly impacting you in your life because of a handful of people on the internet who have a different opinion to you. I mean I know that’s MN, discussion forum etc etc, but people usually have some skin in the game in the thread they’ve started.

Loveandheights · 05/07/2026 09:33

People on mumsnet have had kids and seen it all. They aren’t judging, they know you’re getting used. We look back on earlier years and dynamics and see the truth. We’re also old enough to watch our 40M friends try to date women in their early 20s and see how unbalanced that is. You’ll understand one day. If you love the person enough, go for it despite what anyone says. Everyone lives and learns through this process.

TransportNerd · 05/07/2026 09:24

wheresthesnowgone · 05/07/2026 06:42

And you'd never be able to date someone your sister once looked at.

😂

OP posts:
OneFineDay22 · 05/07/2026 08:25

kkloo · 05/07/2026 01:41

And if you had an adult child 30+ and they introduced you to their 18 year old girlfriend?

Yes, and this

TransportNerd · 05/07/2026 08:06

coocoocachoop · 04/07/2026 23:54

And do you take people this literally in real life?

Well, the person I was talking about who has repeatedly and seriously argued it should be made law has just predictably reappeared to do so again.

OP posts:
wheresthesnowgone · 05/07/2026 06:42

DarkForces · 01/07/2026 08:18

I think most mumsnet rules are safely ignored. Life would be very dull and toilet brush manufacturers would be broke if we all followed them

And you'd never be able to date someone your sister once looked at.

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