cheat

Hi lisa I ll appreciate it if u can hide my identity, I need some really mature opinion as am in a confuse state. I have a 5months old daughter with my fiancé , we are suppose to get married mid next year, and all wedding preparation are already in process only to find out from my friend that he slept with my sister, I confronted both of them n they admitted, apologizing that they were drunk, all I want sincerely is not to ever see both of them again n call off the wedding but each time I look at my daughter I get confuse cos I don't know what I ll tell her about her dad when she grows up,do I go ahead with the wedding or call it off cos I really don't trust both anymore