They were together for seven years before getting married. They were married a year-and-a-half and then got divorced. She almost immediately moved in with another guy in the friend group.

I actually had suspicions even before they got married, based on how she interacted with the guy friend in the group. He was a walking nerd stereotype; afraid to talk to women. Always having issues with dates because they found him too weird (surprisingly her words, not anyone else's). She was always trying to help him with women (supposedly), and was oddly proud of how she was the only girl he'd really talk to.

She says they weren't, but I'm pretty sure they were doing more than talking.

I never said anything because they were only part of my "friend group" through my husband, and because I had no concrete evidence. But it was so obvious to me something was going on, and I'm surprised no one else noticed.

She cut off contact with everyone a few months afterward; probably because she moved away but assumed it was because we took his side. I mean, I took his side...but I think everyone else was just treating it as a "this breakup was mutual with no one to blame" situation, and hung out with him more because he didn't move.

We saw her a few weeks ago and she had diamond rings on both her ring fingers. She's only been with the guy (officially) for a year.