My best friend is dating my sister
I dated my long-time friend and at-the-time roommate's little sister last winter.
The only issue he had was that my room and his shared a wall, and she is not the type who is quiet in bed.
My buddy married the sister of one of his lifelong friends.
The brother couldn't be happier because he knows my buddy is a truly stand-up guy.
When she did come to visit 2 years later, C's best friend in the fraternity, who was notorious for his lack of success with the ladies, wound being the one who banged her.Punky Veer: Your best friend is probably that one person that knows almost everything about you, including your relationship history, depending on how long you've known them.So if they disapprove of a relationship between you & their sibling it could mean two things 1)they think you're scum & not good enough for their sister 2) they don't wanna have to pick sides should things not work out between you two. But still, I know too much about them to ever be comfortable with them dating anyone in my family.If it's the brother that treats women badly, he tends to assume his friend will treat his sister that way based on his own perspective: if it's the friend with the bad record, the brother knows how the friend treats women and doesn't want to see his sister added to the list. Then my grandpa's brother married my grandpa's wife's sister.It seemed to work OK for them: all three couples had happy 50 year marriages and were parted only by death.
I don't ever recall hearing that one is not supposed to date one's friends' sibs.