text: my sister is having sex in our living room!? my sis is 18 and she is in our living room having sex w/ her boyfriend. my parentsare home! what am i supposed to do? umm stop her!!! and tell her shes being slutty and is going to get pregnant and tell her her boyfriend is cheating on her and he has an std cuz its the truth.  ps, dont b a skank like her!  b a good girl and find a good man, dont give it all up to the first dick u c.