Far enough as long as you agree to the same. Honestly that has always been my opinion. With it been a guy to girl, girl to guy, guy to guy, or girl to girl. I say only if the other is far to young or old, than maybe ok.
You guys do know that girls mostly say that when they do like the guy, but they just don't want him to find out. It'll mostly turn out like: ewww no, if course not, what us *blushes a lot*. I'd take it as a compliment :)
I FUCKED UP