my 18 year old cousin who lives with us wants her boyfriend to spend the night. my SO said that decision was up to me cause id have to deal with her father. shes 18, in college, works, and does give us rent money. she has her own room here and all. she helps out around the house. shes living with us because she doesnt get along with her mother and her father only lives in a studio apt. her father wouldnt allower a coed sleepover but i dont know. im not stupid i know shes sexually active. im stuck with this one.