Do I tell my friend her boyfriend is cheating on her with her cousin?

my friend has had a rocky relationship with her boyfriend like all of us one day she confided in me and taught there was something going on with her boyfriend and cousin anyways I went to meet my boyfriend in the pub with his friends and in the lounge my friends boyfriend was there with a girl I recognized even though the place was packed I seen her with her arms around his neck kissing standing together his hands on her rear end anyways facebook told me its definitely her cousin so do I tell her ive been avoiding her like crazy because I no the truth but I dont want this turning on me like thats family need advice

Yes you tell her, then you comfort her until she feels alright.

yes you should tell her, first it caled being a good friend and second thats not fair to her that hr bf and her cousin are cheating. I suggest you tell her, and yes comfort her. its better to tell them before she finds out the hard way and gets hurt far more than she needs to

I think she should know, since no one would want to get cheated on. She might think you're having a laugh. I reckon you should get some proof first just incase she doesn't believe you. GOOD LUCK (;