AIBU to think this is an inappropriate relationship?

Agree completely but I would apply your responses to 7 and 8 to points 1 - 6 too!

She's been in his life since he was tiny so why wouldn't she cuddle him, put him to bed and tell him she loves him?!

Jesus step-mums can't do bloody right for doing wrong!!!

I can see why you resent the step mum.

At least the step mum puts effort into caring for your son, but there doesn’t seem much evidence that you do?

I can’t believe you don’t want to have your son with you at least every other weekend? As for holidaying with friends and not your only child is astonishing to me.

Maybe you should encourage the boy to live with his dad full-time and then you won’t need to bother putting up with him at all?

All the things that you deem "inappropriate".. do you do those with him?

It sounds like she has put in the hard work and actually cared for his emotional wellbeing, and you took the easy road of sending him to your ex for any time that you would actually have to parent him, and now you are wailing foul!

He is a lucky boy to have so much love and support from your ex and his family, but if you aren't careful you will end up with nothing . I know where I would rather be if you start being jealous and difficult with him.

Perhaps listen to "cats in the cradle"..
..and I'm sorry. This must be so painful, but you made your bed.

You really have to own your parrot in this, @Playnoway .

You like going out at weekends, so delegated all the bonding time when there's usually less structure/more relaxing/fun times to your ex and his wife. Naturally, they've all developed a closer bond.

You find holidays with your son difficult, because he wants to be active, like most children do. Instead you went away with your friends for even more jolly and relaxing.
Your ex and his wife provided fily holidays where your son gets to spend time building relationships with his extended family and likely doing activities that are centred around or at least include activities he enjoys. Again, fostering a close bond...

Your ex's wife is more present in school than you are so is friendly with more parents. I am guessing she also makes more of an effort to cultivate relationships with hos friends' parents and those of her child, so again, seems more present for him.

With the amount of time they spend together (outside the regimented school week), he has time to unwind, open up and share his feelings etc with her. His dad, like so many men, likely leaves the physical and emotional labour to her and she's obviously a warm, loving and safe space for him. Naturally, after so many years of being there for amd with him, it's makes sense they share a close bond.

Have you considered getting out of your own way, being available on weekends, doing activities he enjoys and maybe then, you can start forming the kind of relationship where he wants to go away with you? There's no point being jealous and complaining if you're not going to take the necessary steps to close the gap.

OP, people really do understand what is hard for you here but your son is not an extension of you, he's his own person with his own relationships, which you should not seek to control unless he is being harmed in some way. It can feel hard when a child has a close relationship with a stepparent (I speak from experience!) but your son's relationship with his step mum is his. In the kindest way, you are being completely unreasonable about every item on your list. You're not his best friend and shouldn't seek to be - you're his mum. She isn't and won't ever be so best friend is just his way of saying how important she is in his life. It really isn't weird that they love each other nor that they have a strong bond and spend time together. This lady isn't part of your family but she is part of his and honestly, you should be pleased that when he goes there, he feels part of a family unit and wanted and valued. There is absolutely nothing you can - or ever should - do to change this because that would be very controlling behaviour towards your son and actively detrimental. You need to have a big grown up think about not allowing your own feelings to control you, especially so where that would be damaging to your child.

You chose the days your son went to his dad bc he worked during the weeks & you enjoyed going out on the weekends.....
Never took him on holiday
but managed to go with friends bc his dad took him.....(well someone had to i guess)
My word.... Have a long hard look at yourself. Did it ever, in the whole years of having ds occur to you to not take him away just for one weekend every so often to spend more time with him rather than just his dad taking him? (im pretty sure his dad wouldn't have minded him & his wife sound very accomodating).
She has a better relationship & bond with him than you do, the schools mums like her more than you. You're clearly jealous of this woman.

Good on her, she sounds like a fabulous mum and step mum. Maybe you could learn some tips from her and start to prioritise your DS.

I find your comment about why you don't take him on holiday a bit odd.
No 9 year old is likely to be interested in "just going to the pool and relaxing" as they are a bundle of energy, excited to be somewhere different and looking for things to do!
We all go on holidays which are child-centred when our kids are young and put on hold the type of holiday we used to enjoy before we were parents - that's just how it is

Your ‘pain’ is all of your own making so no sympathy here.

You created vacuum and somebody filled it.
Step mum sounds wonderful!

could you not try renegotiate some weekend time?

You ask whether you should consider changing the arrangements for custody.

This would seem a good idea so that you can spend every other weekend with your son. This way you could have outings together and build up a routine with some special time, just the two of you, in the same way as he has with his stepmother. It's quite unusual for one parent to have all the weekends and may have suited you when he was just a baby but now that he's at school, you don't get to spend much time with him, as you have said.

His Dad seems quite reasonable eg you say he offered to accommodate you regarding a holiday, so perhaps he will also be open about altering the weekends?

Take back the weekends.

You basically gave your son to her. If you want him back and don’t want to feel left out of his life, start organising play dates for the evenings you have him so you know his friends. Arrange his next birthday celebration. Stop being useless. It’s not too late to turn things around and become a more active parent.

I would feel awful too, but she isn’t to blame. In fact, you should be greatful to her. She’s given your son what you couldn’t. Now that you can, just do it. No need to disrupt the status quo because you’re feeling shitty because no one is particularly bothered about you.

Maybe he’s at work? Not everyone works a 9-5

The fact that the step mum does bedtime and after school clubs. Dad has half the week with ds he should be doing those things.

I can completely understand why you don’t feel comfortable with it but let’s face it, she’s not being inappropriate.

She’s loving him like her own and making him feel loved and included. Shes married to his dad and won’t want him to feel pushed out, especially as they have another child.

Thats not inappropriate - it’s a blended family.

I'm sorry OP but you’re being unreasonable. If it were reversed and it was your new husband then I’m sure you wouldn’t see any issue with it, so you can’t really do anything about it. You just don’t like it and feel like you’re not his favourite. I don’t mean to upset you by being blunt but you really need to take an internal look at your motives here. It’s not her that’s the issue- it’s you.

Total rubbish. My DSD is 9 and is very cuddly and tells me she loves me and I say it back. She loves a snuggle with her dad. I don't snuggle because that is crossing a line for me but hugs and cuddles? Perfectly normal for 9 year olds.

He was 3 when she gave him his first cuddle, it would be odd to stop.

Where does it make the dad sound a bit crap? I don't see it?

I have a 10 year old and she most definitely still wants cuddles, as do my friends’ children of the same and similar ages. My 12 year old still wants cuddles too.

No I didn’t mean that aspect was although I don’t agree with it.

I just didn’t do it because I didn’t need to and when I got involved the child was 7.

i don’t think as a step mother you need to be doing that to a 9 year old cuddling them no a quick hug maybe . Most 9 year olds I know won’t want a cuddle.

You really are making all of this about YOU!

You talk about YOUR pain - rather than what your DS is getting from the close bond he has with his DSM

You opted to send him to his dad’s EVERY WEEKEND, because YOU like to go out at weekends - and now your DS is reaping the benefit of spending lots of quality time with his dad and family, YOU don’t like it all of a sudden

You’ve never taken him on holiday because YOU like going away with friends and you find him hard work, plus YOU don’t like the type of holidays he wants to go on

You’re jealous. All the things you list are not inappropriate. It’s just that YOU don’t like it. Sounds like your ex has a great partner and she has put in a lot of effort with your DS. How wonderful of her. You should be happy for your DS and recognise that had you put in more effort yourself, you would also be reaping the benefit now. But you chose weekends and holidays with your friends.

By the way, Hell would freeze over before I would consent to not seeing my DC for four weeks!

But you didn't "let his Dad have him".

You gave him to his Dad because you wanted to be free to enjoy yourself at weekends and on your holidays. You were glad to be free of him, please don't try and present this as some sort of selfless gesture back when he was 3.

You want your son to live for the majority of his non school waking hours in a house with someone who doesn't love him and is just polite to him. Who treats him competent differently from his sister.

That does not sound like being a loving mother to me.

This is such a reverse.

I know a family who had a very similar dynamic to this actually (my neighbours). The son lived with his mum in the week and spent every weekend and most of the holidays with his dad, wife and half siblings. When he was 13 he asked to live with his dad full time and at that point he was deemed old enough to have his wishes taken into account. This was around 3 years ago and he’s still with his dad. His mum goes on a lot of nice holidays!