Under the law, it's just as illegal for an adult woman to have sex with an underage boy as it is for an adult man to have sex with an underage girl. Under the law, a child of 12 technically can't consent to sex with an adult, partly because they're generally considered too immature and partly because of the unavoidable prospects of coersion.

Unfortunately, there is a huge double standard here. Back in 1944, a 15 year old boy ran off with a married woman many years older than himself. His name was Sonny Wisecarver and he became a national sensation. Bob Hope used to make jokes about him and he became famous as the "Woo, woo kid." Hell, they even made a movie about him a few years ago called "In the Mood". Funny, I doubt many people would've been laughing had it been a 15 year old girl running off with an older man. Adolescent male fantasies aside, the law is still the law but it seldom is enforced equally.