TL;DR: I suspect my SIL’s fiancé is cheating on her. What should I do?
I have very strong suspicions he’s (36m) cheating on my SIL (34f) among other things. I won’t get into details here as to not be recognized but he’s been a walking red flag since the beginning. I now think he’s cheating on her and they’re supposed to get married in a few months. What should I do? I don’t want to create drama so I haven’t said anything to anyone so far in the family so far. A friend suggested I create a fake dating profile to find him online but I’m really wondering if it’s too much?