I guess I'm pretty late to this thread, but this trend annoys me too. I've been on message boards where posters (probably still in their teens) were calling childless women who looked to be about 30 MILFs. I think that when you're young, you're useless at estimating the ages of people more than a few years older than you. One obviously teen poster even responded to a picture of what were obviously two sisters, one of whom looked college aged and the other junior-high aged, calling the older girl a MILF and speculating that the younger girl was her daughter. I said "if that older girl is the younger girl's mother, she must have conceived when she was about 8 years old."