Here's data on the "Percentage of Never Married Teen Males Ages 15 to 19 Who Have Had Oral Sex, by Sex Type and Sexual Experience, 1995 and 2002" (table 1):

Even in 2002, the "received" fraction exceeds "given" by nearly 13%, and even more among some ethnic groups. Say what you will about raising a generation of teenagers who have more premarital sex than before (in my view, that's pretty troubling in some ways, inevitable in many ways, obviously less troubling once we get higher in the age range, just fine and on balance quite pleasant for many teenagers who have sex safely and responsibly, and very bad for many teenagers and adults who don't have sex safely and responsibly). But regardless of all that, there's just no excuse for raising a generation of selfish cads.

Among girls, by the way (table 2), the direction of the difference is similar — more reported having received than given — but by a smaller percentage (6% overall). For whatever it's worth, among the richer teenagers (family income at 300% or more of poverty), both males and females have more oral sex, and the "selfishness gap" declines, though the data I cite doesn't control for race or for family structure.

The data of course reports only whether respondents have had oral sex at least once; it doesn't report on the frequency of giving and of receiving. My fear is that the selfishness gap there will be even greater ....