Use your terms correctly wrote:
The "blood libel" against gays and lesbians has always been the predation/grooming of the vulnerable, usually in the teen to young adult years (whereas paedophilia, as Milo notes, is pre-pubescent). This has been true since Roman times, at the very least. The "lowering of the age of consent" (typically to 12 or 13) is one of the big issues for this NAMBLA crowd, so it's no surprise that Milo fits in well.
This fits in pretty well with my experience. College is a typical time for this, as I can remember my college orientation 20-odd years ago, with various "chicken hawk" characters (is this term still used?) eyeing around for anyone who seemed outside the norm, a proctor-planned trip to "certain places" on Melrose Ave, etc. Of course, unless you know the culture, you might think there was nothing untoward. There's also the almost-always ignored differential in the catch-all "gays" between those who penetrate and those who are penetrated (80-90% don't "swing", and many don't even use the word "gay" for the former).
I can't speak for lesbianism, but I sense that LUGs (lesbians until graduation, i.e. women who get so sick of boorish guys, but still want to live their "sexual potential" while at college) are a more native phenomenon, with there more usually being near equality of status between the participants. OTOH, whereas gay male profs are unlikely to seek out students, this seems (slightly) more common from lesbians. None of this is anywhere near as common as the rampant heterosexual hook-ups of course, but for that the expectations are usually close to mutual.