Sons relationship

[Heliophilia]

I have 3 kids, my middle son is 21, his birthday was in October. He is in his 3rd year of uni but lives at home, had the same part time job since he was 16.
Recently he has told us that he is in a relationship with his school best friends (now moved away for uni) little sister - she’s 17, 18 in the summer in Y13. They work together and have been doing so for about a year and a half. Apparently they’ve been dating for about 8 months (so 16 and 20). His friend who he’s still close to had no idea and has only found out recently, same for us parents.

Well it’s all blown up, his friend is accusing my DS of having slept with the girl before she turned 16 - during the summer before last, weeks before her 16th. He claims this isn’t true and they only slept together after her 16th and starting dating when she was closer to 17. She didn’t start working with him until she was 16 and he said this is how they got closer so I believe that.
He won’t break up with her and she doesn’t want to break up with him but all of his school friends are a bit outraged and he’s now barely going out (he has uni friends but they aren’t the type to really go out), I’ve told him I don’t like the idea of him being in this relationship so she can’t come here and I believe her parents have said the same, but they work together so are still seeing each other plenty, also think he is booking a hotel or similar at times to spend the night with her as I know he’s not out with his school friends and he’s never stayed out with his uni friends before.
I know he’s an adult so his relationship is none of my business but she isn’t.
AIBU to be concerned and wanting to talk to her dad? Or do I just leave it?

I have never understood this weird thing brothers have about their sister's sex lives. I was saying exactly this to someone just the other day actually.

I agree but his dad does seem to have his back.

Yes, if he has any brothers I bet he doesn't gatekeep their virginity.

I'd move in with the "relaxed" normal father!

Literally nothing to do with anyone else apart from them. It's a rumour until proven otherwise and how would it even be proved anyway?!

No one is the gatekeeper of their relationship, not you, her brother or her parents. Keep her out of your house by all means but be prepared to see less and less of your son for what is essentially a silly reason.

I feel like there’s probably more going on between him and his friends to lose them over what you think it is.
I’d probably wager a bet that he’s become pretty attached to her and might be ditching his friends or always trying to bring her along when things might be more a friends only event.
Either way I really don’t agree with losing friends over a relationship, especially if they’ve been good friends over the years.

Saying she can’t go to yours is one sure fire way to push your son away.

your creating a them against us situation which is never good. They’ve done nothing wrong from the sounds of it, your believing the rumour and your actions are telling your son that.

besides, you never know, she could end up the mother of your grandchildren. She will remember this.

Because her son is suffering because of the rumour?

The friends aren't really very good friends. I suggest you support him and the relationship or you'll drive him away.

She's 17, so your son isn't doing anything wrong, therefore I think it's unfair to effectively punish him just because people are finding it difficult to accept.

It would be extremely shit to dump your girlfriend over peer pressure.

Why not be nice and welcoming to her instead?

I think you should allow them to meet in your house.

Ok maybe not overnight stays but what happens if they settle, marry and have kids and you did not let them hang out at your house.

Ignore the friends things. True friends would believe him.

This all seems like a massive over reaction. I don't understand why there is any reaction to be honest. Are a bunch of 21 year old guys (presumably your son's friends are roughly his age) really going bananas because she might have slept with her regular boyfriend when she was 15? Is there a cultural or gang element to this?