Your friend's older sibling.

Everyone has a friend who has a sibling who is attractive.  I have about at least five friends with a brother I have daydreamed about.  At least.  I don’t know why I haven’t dated any of them, I’m clearly the mature friend.  (It may be because I didn’t communicate any level of interest.  Whoops.  Or the fact that they are used to their little sisters' friends getting googly eyed over them.)  Mostly I think it’s because I’m such a good friend, and never want my female friends to feel abandoned by me for their beautiful brother.  But I hold on to the hope that someday one of these guys will realize that I’ve grown up; and my friends will realize that they would rather have me at family reunions than some psycho.

Until then I’ll just make sure I’m my friends' plus one at all family functions and show an unnatural interest in whatever sports game the older brother is watching.