But these days, there's even more reason for concern."Kids almost seem to be running the bases backward," says Marisa Nightingale, of the National Campaign to Prevent Teen Pregnancy, referring to the new sexuality.

"I have an 11-year-old middle schooler who came home saying that a boy wanted her to have oral sex with him in the parking lot," says Tonja Krautter, a psychologist in Los Gatos, California, who works with adolescents.

"A lot of kids have this idea that it's no big deal." Kids who think this may be missing crucial messages about sexually transmitted diseases and self-esteem.

Talk to your kids about the seriousness of any sexual contact.

Still, in all likelihood, they won't want to hear the particulars from you.

"He pulls in and gets on his cell phone and says, ‘I'm here,'" Beck recalls.

"I said to my daughter, ‘Tell him he needs to come in.

Beck demands that her daughter turn off her cell at on weeknights and at midnight on weekends (before this, calls were coming in as late as a.m.! If you're concerned about calls your kid is making, another strategy is to use shared minutes on family plans; that way, you can scrutinize the phone bills.

(Also, be sure you know the numbers of your child's friends.) Internet sites like myspace.com, facebook.com, and xanga.com, where teens can post pictures and trade messages, allow kids to meet tons of new people.

One woman with three sons was astonished last summer when a girl took a liking to her 15-year-old and got aggressive. Teen pregnancy numbers are down, and so is the number of kids who are having intercourse.

But that doesn't mean kids aren't sexually active: Studies have found that some 50 percent of teenagers, ages 15 to 19, have engaged in oral sex.

The hours between and p.m., when many parents are still at work, are prime time for trouble.