Have you ever been friends with a couple and knew one was cheating? Did you say something or stayed quiet?

my situation isn’t exactly how I worded the question but whatever. I’m cool with all 3 people involved, I work with all of them. Person A and B are dating and person C is messing and talking to Person B.
I hate cheaters and I feel like guilty knowing that Person A is being cheated on, Im not super close with him or anything but he’s a super nice person and I feel really bad for him.
Person C is someone I've known for a while, i used to be good friends with his brothers. Now both of his brothers have beef with me and one tried to fight me so if I say something, all 3 of them are gonna jump me or some shit 💀 I have enough high school ass drama with that family and I don’t need anymore. Im surprised Person C is friends with me considering his brothers hate me lmaooo
Updates
+1 y
I also forgot that person C also has a girlfriend lol
So now only is he homewrecking someone’s relationship but he’s a cheater himself. He’s been telling me for a while that he’s been unhappy and he’s not attracted to his girlfriend anymore. He’s been trying to break it off and tell her how he feels but she freaks out and he feels guilty breaking her heart or something
Today he said “I just realized that maybe IM the drama” like you think? 😭
Have you ever been friends with a couple and knew one was cheating? Did you say something or stayed quiet?
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