There's a difference between pedophilia and ephebophilia.
http://www.depression-guide.com/ephebophilia.htm
In short, it's normal to be sexually attracted to teenagers (hey, we were all 16 once), but that doesn't mean it's alright to try and strike up a relationship with one when you're well out of her age-bracket. Just like it's inappropriate for a 30-year old to be fooling with an 18-year old--even though when I'm 30 I'll still see 18-year olds as fuckin' hawt. Some things are best left as a harmless *fantasy.*