SIL cheating nightmare

[LadyJane99]

I have name changed because this could be outing and have implications beyond me and my family.

My SIL said something to me in passing that made me wonder whether she’s cheating on her husband. I mentioned it to DH who claimed ignorance but right at the end of our conversation I could just tell that he knew something. He ended up telling me that she’s using a website to meet other men. She’s dating two of them at the moment. Apparently it has worked wonders for her marriage although of course her DH has no idea. She says that her DH adores her and I personally suspect he would never leave her, even if he found out, which is presumably emboldening her.

Apparently she’s happy with this arrangement, isn’t looking to split up with him or anything. But the thing that she said to me originally made me suspect that she’s forming an emotional attachment to at least one of these men. I think it’s going to end badly.

Furthermore, I’m concerned that my DH hasn’t expressed the slightest dismay at the situation. He adores his sister and thinks that whatever she says or does is right. In fact, the reason they were chatting was because he and I have had relationship problems and I suspect she’s encouraging him to use this website too.

So, does anyone have any thoughts, insights, experiences of anything like this?

I should add that they have been married about 20 years. They have 2 children and could easily be financially independent from each other. I have to socialise a lot with my BIL which I’m finding a bit uncomfortable because I feel sad for him.

This website is for married people to hook up.

I'd be incredibly disappointed in my husband if he didn't think she was doing anything wrong. It'd really change my view of him.

How long has he known?

I think he’s known for a couple of months maximum.

I was really unsettled by his reaction to this. I know that he adores her and would support her 110% but he has known her husband for 20 years. My DH just accepts that his BIL must have flaws that have driven SIL to this.

I think DH thinks he can’t say a word against what his sister is doing because he would feel like he’s betraying her.

That would change my opinion of my husband and definitely of her. Not sure I could sit back and say nothing to be honest... That would permanently colour my view of both of them especially the sister. I could not associate with someone I knew who did that sort of thing without a second thought.

I'd be working out ways to let the husband know without it coming from me directly and distancing myself from the sister completely.

I'd tell DH that if he thinks him going onto some kind of swingers website is fine & dandy then he's married to the wrong woman. Further, that he'd look far & wide for any woman to think this ok. Since he thinks the sun shines out her arse regardless of how bad a human being she is how far exactly is he prepared to go to convince you & the world that what she does or says must be 100% right? He's pathetic, his sister is some minger who doesn't deserve a good & faithful man & you're in the position of having to decide if you have any morals worth mentioning.

Yes I do. One of my brothers has been on these sites, and his wife has gone mental with ptsd, after she found out 3 years ago. She’s been poisonous to my dad, her dad and close friends. They won’t divorce and he is doing everything to try to amend things. He wants me to befriend her. She hates our family anyway, and I’ve never liked her. I think they are both stupid for not divorcing. I want to run for the hills and let them wallow in their mess.