I found out yesterday that my sister's boyfriend/father of her child is probably cheating on her again. Yes I said again. I found out that he offered a "dancer" $1,000 to meet him at a hotel. The "dancer" said that she never actually agreed to meet up but that's not the point. I KNOW the "dancer's" story is true bc the "dancer" told my room mate to tell me about it; she named my name and she named my sister's boyfriend and also what he does for a living. It turns out that my sister's boyfriend actually told the "dancer" that he knew me and my room mate(who is a manager at the club she dances at). The dancer did not know who I was UNTIL my sister's boyfriend told her how he knew me and that I was her manager's room mate. I guess he didn't expect her to tell her manager about the offer he gave her. My question is what do I do??? I don't really want to be apart of the drama that will obviously come with that but its my sister!! Even if I don't tell her, I'll still have drama coming my way if she finds out that I didn't tell her. Please please please help me make a good decision. It's all I can think about. I feel horrible for not telling her but I know how my sister is.. she doesn't like change. She is only pulling in minimum wage and raising her only child, another family member's son, and her 18 year old cousin. I don't know how she could do all of that if he wasn't there because he's the breadwinner between them. What if he contracts an STD and gives it to her?? I am losing my mind with worry. Any advice is welcome.