DP friends with people much younger, then “hanging out” in her room

I think a male of 26 is emotionally nearer to a female of 20 than 30

It doesn't seem that (on the face of it) he's done anything wrong. But I feel the issue is the difference between you regarding lifestyles. The question is, do you see this as a long term thing or just a bit of fun? Is he on the precipice of wanting to settle down? What you're wanting and what he's prepared to give may be two different things and if that's the case it may be worth breaking it off.

He's scoping out a replacement and checking if you're going to be a "cool girl" about it. Personally if you're still having fun ok, keep goingif you want, but I'd keep an eye on it and be the dropper rather than the dropped.

Ok that doesn't sound as bad as it did in your OP, where it did sound really quite dodgy, but it still doesn't sound good for a man in a relationship. Friendships across age groups is quite normal in work environments, one of the people I get on best with at work is 13 years younger than me, but it sounds like he's not the right fit for you. If it really is just a casual thing for you then that's fine, carry on and have fun, otherwise maybe end it because you are questioning things and there's usually a reason for that, even if you're not sure what the reason is, maybe just a gut feeling.

When I worked in similarly sized offices we socialised across age ranges and there were friendships with big age gaps - even mixed sex ones, but it’s the waiting in an 18 yr old’s bedroom that is ‘off’ and your bf just having a completely different lifestyle to you.

I get that hanging out with an 18yo seems weird to you as a 30yo with a house and a child etc. But he is younger than you and at a different life stage...26 and still living in a houseshare etc. If the 18yo was still at school, I agree that it would be weird, but they are colleagues so I don't think it's that unusual. Especially as young women are typically more mature than young men in any case. Plus an 8 year gap really isn't that different from a 4 year gap imo, it's more about where people are in their lives at any given time.

So I don't think there is necessarily anything weird about the friendship, but if your gut is telling you that there is something more to it than just friendship, then you're probably right. Either way, it seems that you don't really trust him so maybe time to move on?

I'd dump him. 26 is probably too old to be hanging round with 18 year olds but he sounds quite immature. He's probably thinking he's still young, which he is, but he's nearer to 30 now and wants a relationship with a woman who has a child. I can't see him providing you with what you need in a relationship. If you're looking for something long term then I don't see the point in carrying this on because you'll only get more drawn in and hurt when it's over, even if it's just fun for now.

You are very quick to defend him and his behaviour OP.
If you don't have a problem with him socialising like this then fair enough.
Just let him get on with him enjoying his life.
I thought the point of the thread was that you weren't happy with him socialising with all these young women?
He is obviously enjoying the new dynamic at his workplace to the full.

Please ditch him, you two are poles apart in life stages. I really don't think he should be in a relationship with someone who has a child, he's far too young himself. I really can't see this working out between you.

He was in her room whilst she got changed and then they went out drinking alone together? wtf

OP I would do yourself a favour and find someone older. 26 imo is still young and whilst I was in a long term relationship at that point so many of my friends weren't and were still in party mode. You had a kid and a house and he's in a house share and partying. You are in different places.

Sounds pretty casual to me. You’re having fun with someone that you know isn’t going to be long term, he probably feels the same way, a ‘good while it lasted’ fling…🤷‍♀️

Why would he wait in her bedroom while she got changed? Was she getting changed in the same room?

Why wouldn't he wait in the kitchen/living room?

But weird to go into a colleagues bedroom...

He was in her room while she got changed??? And he essentially went on a double date with her and another couple?
It sounds as though he has a lot more than a working relationship with her.
I think you should let him get on with things and find someone else OP if you are looking for an exclusive relationship.

My husband is 28 and often feels people 25 and less are soooo much younger, I feel much the same! Sure you can have female friends if you're a guy, but hanging out in their bedroom on your own? Maybe not!

You say you're having fun and enjoy his company, but that's outweighed by the stress you're feeling about his lifestyle.

It's been 6 months. Do yourself and your child a favour and end this, you don't need the stress. You'll find someone better suited. This isn't all you're worth.

My husband is younger than me. He had no children whilst I did. It worked in the early days because we share the same values - he's about family and loyalty and wanted to spend his spare time with me - not out on the drink with his work mates.

There is someone out there who is perfect for you, and will make you happy and not stress you out. I promise.

Throw this one back.

I'm not one of those who doesn't believe in platonic friendship. However, I think on the workplace you do need an eye on how things look.

Also, that made me laugh because when I was in my early 20s I remember an occasion when 2 work colleagues and myself were going to carry on after drinks, and at the last minute one pulled out leaving me alone with the other. In that case it was a very deliberate setting us up move because she knew I liked him (and it worked, he is now my DH). So he might want to think about why the 24 year old didn't show. Do they know that the 18 year old has a crush on him? Or maybe they knew they'd feel like a 'third wheel'.

Yes that majorly weird.

I'd end it now.

I can't believe people are somehow making this your issue.

You've done nothing wrong.

Given that the male brain/emotiond develop slower than those of females, your 4 year age gap is more a 7-8 year gap. Plus you have had to mature as you have a child.
This relationsship should be fun, because given the variables, it is unlikely to be 'exclusive', particularly as you don't live together.
Lower your expectations of this one, and just have fun. Not a keeper, too much of a tiddler!

Unless he's REALLY into kids, I don't think you can compete with the single lifestyle. They'll all be having fun, drinking, holidaying, splashing cash. Whilst you're thinking about your son, your bills, your family etc.

I can't see it has staying power, he wants an exciting life, hence living in zone 1.

I also can't imagine it'll stay fun for you for long. It's not fun being with someone who wants different things and I think that'll become apparent soon. I'd make sure you keep your options open and withdraw contact from your child if he has already met them.

Tbh, I personally couldn't be with a man 4 years younger than me, it's very well known men are extremely immature, never mind one 4 years younger than you when your at completely different stages of life. I also think him being in an 18 years olds bedroom in her parents house while she's getting changed to go back out is very weird

You are at completely different life stages, he isn’t really doing anything ‘wrong’ as such. He is still in the do what you want, when you want stage and only has himself to consider. Which is completely different to your life. Depends what you want really, if you’re looking to settle down, it doesn't sound like he’s interested in that right now.

What did he say about why he went out just with her for drinks?

I'd have no problem with the hanging out in a group or working together, but it seems to cross a line to invite a younger female he doesn't know well for drinks alone if he's in a relationship, and hanging out in her bedroom is a bit intimate.

So to me it's not really the age that's the issue, it's the potential cheating. Although age does complicate things in terms of the dynamic - he needs to be careful he doesn't open himself up to being seen as predatory on the workplace.