Buried in otherwise unsurprising Reuters piece on a new study on oral sex amongst teens is this line, which suggests exactly the opposite of most anecdotal or empirical evidence I've heard:

It was more common for boys to have performed oral sex on girls than vice versa, the report said.

I don't know the methodology of the study, and this may only reflect teenage boys' greater willingness to say they've "performed" oral sex on girls than vice versa - but even if this study only represents norms about what teenagers think they should say, if more teenage boys who are on the receiving end of oral sex are reporting reciprocating as well, then that's some degree of progress past the all-too prevalent idea that girls should perform oral sex on boys while boys should refuse to do the same in return. Not to say that oral sex is the right call for most teenagers - just to say that any evidence of an increasing sense among our generation that heterosexual physical intimacy should be aimed at the pleasure of both people would be a good sign for many things.