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?

>>5 true. Morals are based on person observation and absorbtion of specific information. With no filters like religion or experience;  we would all be fucking little 12 year old blonde white girls. Experience tells us that 12 is not a healthy age to be having sex, so some people decide to go to a higher age bracket.