A few weeks ago I went ice skating with my FWB "Tricia," her friend "Hannah" and Hannah's boyfriend "Sam." This was the first time I had met Sam or Hannah and I haven't spent time with either of them since, although Sam shares a university class with me and we acknowledge each other if we run into one another.  

After we got home from ice skating Tricia told me that Hannah had cheated on Sam a month prior with one of her ex-boyfriends. Hannah and Sam have now been together for six months and despite not really knowing either of them I feel somewhat compelled to tell Sam about the cheating since I would want to know in his situation. I've talked to Tricia about this and she says she doesn't want to intervene because she'll lose Hannah as a friend and they're relatively close. I'm now torn between my moral compass telling me to let Sam know and my desire to avoid wrecking Hannah and Tricia's friendship. (There is no way Hannah wouldn't know Tricia is the one who spilt the beans so letting Sam know anonymously isn't a possibility.)
user
FWB's friend cheated on her boyfriend
assistant
A few weeks ago I went ice skating with my FWB "Tricia," her friend "Hannah" and Hannah's boyfriend "Sam." This was the first time I had met Sam or Hannah and I haven't spent time with either of them since, although Sam shares a university class with me and we acknowledge each other if we run into one another.  

After we got home from ice skating Tricia told me that Hannah had cheated on Sam a month prior with one of her ex-boyfriends. Hannah and Sam have now been together for six months and despite not really knowing either of them I feel somewhat compelled to tell Sam about the cheating since I would want to know in his situation. I've talked to Tricia about this and she says she doesn't want to intervene because she'll lose Hannah as a friend and they're relatively close. I'm now torn between my moral compass telling me to let Sam know and my desire to avoid wrecking Hannah and Tricia's friendship. (There is no way Hannah wouldn't know Tricia is the one who spilt the beans so letting Sam know anonymously isn't a possibility.)
user
FWB told me that her friend
assistant