A pedophile is someone who is sexually interested in prepubescent children. Since the subreddit was about teenagers, the term you're looking for is Ephebophilia: http://en.wikipedia.org/wiki/Ephebophilia
How many men here wouldn't have sex with a 17-18 y/o if they could be assured no social problems? It's important to maintain some level of rigor in these discussions, otherwise you start doing things like treating sexual interest with a 17 y/o in the same manner as with a 5 y/o. One of those deserves more scrutiny.Ephebophilia is the primary or exclusive adult sexual interest in mid-to-late adolescents, generally ages 15 to 19.
Ephebophilia strictly denotes the preference for mid-to-late adolescent sexual partners, not the mere presence of some level of sexual attraction.
However, the term pedophilia is commonly and mistakenly used to refer to any sexual interest in minors below the legal age of consent, regardless of their level of physical or mental development.[