Because she's a little old? xD
Old? She's 35. I prefer her over her sister actually.
I know this'll seem cheesy and embarrass him, but oh well. I'm one of those types of people who honestly see people (especially of the opposite six) as neutral in terms of looks. I don't look at guys and think, "Oh, he's cute," or "He's hot," or whatever. So my only contribution to this thread can be http://i55.tinypic.com/dxiw5z.jpg which made my then-sixteen year old heart flutter and made me say, "He's cute." It was an index photo before, so that's why I justified putting it up.
Considering he was seventeen in this photo, I can't help but ponder if it is weird of me--nearly twenty-one now--to put that up as evidence of bodaciousness.
It's not weird, and you'll be asking yourself that a lot as you get older. For instance when I was a teen I had a huge crush on http://img849.imageshack.us/i/am009.jpg/, and now years later she's still attractive on Who's The Boss.
My friends and I talk about it a lot. It's a strange feeling. We concluded that it's acceptable because we were also underage at the time, so it's not like we're admiring jailbait.
Try looking through your high school yearbook too, and look for anyone you had a crush on. It's a strange feeling when you're older, a confusing feeling.