I think my dad is having an affair with my best friend. Please help?

The answer is easy ! just hire a PI (personal investigator) . After he/she has hard evidence such as pictures or videos then i would ask my father if he is having an affair with "Angela" & if he dares to backhand you just throw the evidence in his face & not speak with him until he comes clean to your mom & apoligizes too you! Also, I'd just forget about Angela because there's a thinline between getting close to your friends father. If they spend afternoon's together & if I heard that conversation i'd know something was up ! but then again i don't know angela or your dad personally . Good Luck !