Advice?

My sister is dating her best friends brother and her friend is thrilled. I think that if you like this girl you need to do what makes you happy. If this guy is really your friend he'll understand.

Really. you'll trade a friendship for a relationship? Just curious.

As far as the friend's sister goes. you will have to man up and put in a little effort on your part if you want to know more about her. Girls don't like it when guys don't put any effort! Trust me! Do a little research on your part. you don't have to ask your friend about his sister to risk losing a friendship.

Next time you see her, strike up a conversation with her since she knows you're friends with her brother - she's not going to diss you or think much of it in the beginning. It's a good start.

Just remember, girls like a little effort! :-)

I've been the sister in this scenario, and from what I've been through you have to ask your friend if it's okay for you to pursue her. Guys just don't think it's cool at all if you don't ask. I can't say I'm wild about that, it kind of made me feel like property, but that's how it was. And every guy I mentioned it too seemed to react the same way. You should find out if she's single before asking, so you know if it's even worth the bother.