Sexy grades or Sexy sex? Teens can have both! Provided they're in a serious relationship. A new study shows that teens in committed relationships do no better or worse than those who don't have sex. "Hooking-up" teens do worse.

According to the AP:

Teens in serious relationships did not differ from their abstinent counterparts in terms of their grade-point average, how attached they are to school or college expectations. They were also not more likely to have problems in school, be suspended or absent.

But casual sex was a problem:

Compared with virgins, teens who have casual sex had lower GPAs, cared less about school and experienced more problems in school. For example, female teens who have flings had GPAs that were 0.16 points lower than abstinent teens. Male teens who have casual sex had GPAs that were 0.30 points lower than those who do not have sex.

So teens, you have a choice: Be in a committed, boring relationship with one person for all of high school, or have sex with whoever you want and suffer a tiny GPA drop. Either way, you're not getting into Harvard.