A few years ago I was in a long term relationship. This ended largely due to DP having a fairly serious affair (3 months +) with a friend of mine. I had encouraged their friendship whilst I had to go away, thinking this might help solve loneliness on both their parts.
Upon finding out about this affair, I was so shocked and disgusted I couldn't react. I maintained a fairly civil relationship with DP (ex by this point of course) but had little to do with exfriend. I had a pretty terrible time, told no-one, and came very close to suicide.
I am now a more assertive person, less afraid of confrontation, and I have a growing desire to contact exfriend and ask why it seemed acceptable to do this to me. I strongly regret not having this out at the time.
Would that be mad? The main thing holding me back is that exfriend may contact exDP to consult on how to reply, which would be awful. I don't know if they maintain any contact. ExDP now has a new serious cohabiting gf.
I now have a new DP and it is not due to regret that the relationship ended. I am much better off in all ways now.
It is just such a deep hurt and I never received any answers. To say it haunts me is too strong, but it's always in me. The mystery of why two people who I cared about, and treated well, thought this was an OK thing to do.