theres this grl i really like, but her brother is one of my best friends, how should i ask her out?

Sweet.

I suggest visit her 'brother's' place a lot. Include her in the conversations. Let your friend know you are interested in her! Get his approval before you do a thing. Even if you just start out with a small comment about his sister being pretty, gage his reaction first. If you get the alls clear then just ask her if she wants to go out somewhere just the two of you.

I suggest talking to your friend about it first to see how he would react to it.

Nothing is worse than finding out through other people that your best budd is dating your sister behind your back.

And if he says NO, then respect it and walk away. Bro's over ho's

If your friend does not care if you date his sister and you are going to treat her right...then just step to her with a casual conversation and then get to asking her out on a date, maybe to do something you both have in common.

just tell him politely. if u surprize him, u dont have a chance to see the weekend. and this is ur last yahoo question.