Age Difference

I know there's lots of joking around here about lolis and pedos and whatnot, but, seriously, what is the biggest acceptable age difference?  Lately, I've found myself attracted to my friend's sister.  Thing is, I'm 24 and she's 18 (freshman in college).  I feel kinda bad about it.  I feel dirty just for thinking she's cute.  And I'm not all "zOMG she's teh hawt I wanna sex0rz her," I really like this girl.  Should I feel bad about it?  Should I try to persue something with her, or just get over it?  Would my freind get mad at me for going after her little sister?

Dude, people have had 10 and 15 years difference and been happy together. An older couple I know was 15 years apart and they were like 60 or something and still happy. It can work, but the starting age is all that matters really. 18 is legal, so it's up to you so see it through to anything more than sex if YOU want that to happen.

As for her little sister, go for it. I hear a shanking's awaiting you in prison.