So I just moved to grad school and have a few housemates but one in particular is cheating on her bf with a friend of ours. I’m not extremely close with the side boy nor am I close with the bf. But since she’s my housemate I’m pretty close with her. Her bf lives about 2 hours away and only visits once a month but always sends flowers and constantly texts/calls. Every time he comes to visit, she asks us to not mention the side guy. As someone who just got cheated on (and isn’t still over him), I feel like covering up cheating is almost as bad as actually cheating itself. On the other hand, this girl already has a very sassy personality and if I tell the bf, she’ll make my life living hell. Not sure if I can live with myself knowing we’re lying to him when he visits though...thoughts?