best friends sister... would you?

The forbidden love i suppose. This isn't just about sex, this is about love and a meaningful relationship.

If you've had a really good friend for about 5 years or so, and he had a sister who you adored and could see yourself with, you knew she liked you and could potentially become something long lasting. would you take the chance of disrespecting and losing him as a friend, but having a relationship with someone you could truly love?

i'd like to know pros and cons to this. my brain fools me when i'm falling for someone. I don't want to make the wrong decision. Any advice would help me.

>>7
If any of my friends asked to fuck my sister, I'd tell them, "Just don't catch any STDs.  Slut's full of them!"

Come to think of it, she'd be loved on 4chan.  She did a threesome with some guys once... when she was 13.