Please read and HELP~! HELP HELP!!! Thanks?

Relationship troubles! Well I would tell your sister, "Ok look I know you think you should be friends with whomever you want, I had a summer fling with your friend,and I just want you to know it is ruining my relationship with David. I know you don't want to lose a friend beause of your sister but just think about putting blood before friends. Just THINK about having your friend come around a little less than he is currently. Thats all im asking!" I hope that helps.