Sister dating my ex

[LookOverHere]

My younger sister bumped into my ex boyfriend at a party, said she fancies him, said I’ve moved on, so it’s no problem to date him right? I feel surprisingly upset about it and have never dealt with this before. I know it’s not a crime to date a siblings ex; it happens, many would have no problem, but it feels upsetting to me. She is criticising me for being “possessive and sad”, accused me of still having feelings for him (I don’t in that way, just fond memories) and is calling me jealous. He just wrote me an email also calling me sad and why can’t I just let her be happy. It feels like a gang up and I’m in the way, and I’m getting a lot of criticism, although I haven’t said much. I just haven’t given an enthusiastic green light. They’ll go for it anyway, I think. I’m a new relationship and fairly happy in it, I just feel ick at a guy getting a chance to compare us sexually, and feel a bit thrown under the bus by my (ultra competitive) sister. AIBU?

That is disgraceful and awful. Op, you are definitely not being unreasonable. There are thousands of men out there, no need for your sister to date your ex.

Oh that’s a big hell no. I would not like that at all. Not from a ‘love’ feelings pov but because they will talk about you and it won’t be nice. She’ll be the fab shag, your sister was shit kind of thing. Unless you have another younger sister to go out with this fucking loser after her then she’ll never feel the pain of what she’s doing. She’s a horror.

Ew that is just gross. Did your sis just magically decide she fancies him or was she lusting after him when you were with him? Nice of her to go behind your back and say stuff about you giving him fodder for his e mail. At the end of the day she knows you can’t stop her as they are adults but they are behaving like a pair of animals .

Tell her that she's welcome to your leftovers and that while he wasn't good enough you, if she's happy with mediocre then who are you to stand her in way.

Tbh, they both sound fairly lousy but well matched.

I suppose they can do what they want.

But it is a controversial line to cross.

And your sister will have to accept that her decision to pursue this is an event that will have a lasting impact on your relationship with her.

Laugh at her and him. Act like you don’t give a shit if she does, though maybe find it a little funny and a little embarrassing for her to shag your cast offs.

The more it bothers you, the more thrills she gets from doing it.

When they go low OP you go high.

possible he’s trying to be in your orbit seeing as you have a new relationship? Trying to get close to you?

Did he love your family? Want to be back with your family and she will do?

It's gross tell her to find someone you haven't shagged!

He should be off limits. And very stupid of him to send you an email like that. I can't really see that this is a longterm thing in his head and he is planning on seeing you at family gatherings.

Weird and creepy.

YANBU
That said, I once au-paired for somebody that was married to her elder sister's ex-husband! She now had two kids with him. Her elder sister and him had never had kids but she had married again and had them subsequently with her second husband.
They all (the two sisters, the two husbands, the cousins, the MIL) used to have very long meals together every weekend and no-one batted an eyelid/everyone was cordial/ no awkwardness at all. This was in France and they were very Bof! about it all, while wide-eyed innocent me was Sacre bleu!
I thought it bizarre/louche but spoke to my boss (the younger sister) whether it had ever felt weird/how they met and she was Nope, not weird, knew him when he was my BIL, sister and him split amicably, she gave me permission!
Zut, French couples with their open-mindedness!

You grew out of him and stayed separate from him for a reason. Let her date him and find out for herself what's wrong with him.

A friend once asked me if she could date my ex; I laughed and said "he's an arsehole and I think you're a fool to hook up with him, but if that's what you want to do I won't stand in your way."

She dated him for a few weeks, he was a twat to her and she came to me, apologised and said she wished she'd listened because he was a complete arsehole 🤷‍♀️

That certainly takes having a type to the extreme

weird that she wants your cast offs and weird that he emails you, maybe he's trying to rub it in? sounds like a lot of jealousy from both sister and ex, back away from them both.

Well I think most people would feel as you do. Not just because you've got previous with the guy- although that is a definite factor. Mainly because they're centring you for some weird reason. Leave them to it and rise above it.

Be quite dismissive. 'look, it's not a big betrayal. Steve and I dated years ago and didn't really have a future. It's just a bit odd. You don't need me on board and I don't have any particular objections or investment. Just get on with your relationship. I'm not interested in any further discussion or emails on the topic'.

There is more sisterhood and understanding here than in my actual sister relationship. Thanks everyone, massively appreciate your various views. Happy Easter wknd to all x

LookOverHere
For all some people say Mumsnet is full of vipers, on the whole my experience is there are a lot of posters willing to help other women and stand in solidarity.

Your sister and ex are behaving in a weird and competitive way with the messages and gloating. It's no surprise you're finding it weird.

Sex with both sisters? No thank you.

Plenty of men in the world, you stay clear of sisters and friends ex’s

What happens when there is a family 'do' and your sister brings along your ex?

I can't imagine wanting to have sex with someone who had slept with my sister. Ew.

Wrong use of the word jealousy again. Everything is not jealousy. Why would the ex be jealous of the OP?

It's weird and I wouldn't want to have sex with someone who'd been inside my sister. But nothing sounds like jealousy from anyone here.

OP is just saying to your sister that she can do what she wants but no way would I want to have sex with someone who'd been inside her. I'd also be thinking he only wanted to sleep with her to fulfil some fucked fantasy and I wouldn't want to be fantasy fuck fodder

To him. I'd say (if anything) ew. Just ew.

I would say that your feelings are normal. This happened in my family and it was hidden from the older sister for a while. When it came out the two sisters didn’t speak to each other for many years. Sister who dated ex is married to him now with kids but it still seems weird. It would be even weirder if the kids found out somehow as the other sister is married with children and the cousins are close.

🧡