There was a ridiculous number of guys (and girls for that matter) at my sixth form who didn't seem to realise that someone being so drunk they could barely stand wasn't consent to be groped or have hands shoved up their skirts/down their pants. Like, I know it seems like common sense, but apparently some people don't seem to have quite grasped the idea of consent - the fact that dancing with someone isn't agreeing to sex, accepting a drink at a bar isn't agreeing to sex, spiking someone's drink with extra vodka etc to get them to "lighten up a little bit and have some fun" (aka get them drunk so they'll sleep with me) isn't what you should be doing.
Most people probably know that dragging someone into an alley and forcibly raping them is, you know, illegal and a bad thing, but there's quite a few people who think that if it's not forcible, then it doesn't count as rape. Coerced consent ("I'll give you a lift home if you do A/B/C, but if not then I'm leaving you here without a way to get back") or deliberately getting someone drunk to have sex with them is apparently acceptable according to a (terrifyingly high) number of people that I've seen on TSR and in real life.