What do you think happened?

So my friend (lets call him PastyFace) tells me this drunk story:

PastyFace was celebrating some student occasion or another with a drink with some friends when he was led to a party with some (presumably) frat bros. Now PastyFace is pretty tall and big, but he's surprisingly lightweight when it comes to alcohol. I'm not talking about lightweight-for-his-size, I'm talking a-12-year-old-girl-could-shame-him lightweight. Seriously, I've seen the guy have half a pint of beer and then proceeding to engage strangers in conversations in Gibberish.

Also, another important point to note is that PastyFace had an ongoing crush with HotGirl in his university. He'd been contemplating approaching the issue, but for some reason or another (e.g. exams, homework, lack of testicles and so on), he did not pursue the HotGirl issue further than drooling after her at some point or another of the day. They were acquainted and I think were pretty OK friends, but as far as I know she probably wasn't going to write him no tearful goodbye come graduation. He tends to talk a lot about her when drunk.

Anyways, back to the frat party. While Americans mostly drink lightly, which is to say, high on the volume and horseplay but low on the kick, it proves more than a competent match for PastyFace's pathetic tolerance. So PastyFace has way more than he can, and gets massively, massively drunk. He claims not to have remembered anything apart from playing a lot of Beer Pong, does not remember when or how he left the party, who with, and so on.


....


The next morning, he wakes and finds himself in HotGirl's room and bed. He has his shirt on, but nothing much apart from that. He has a massive headache, and just then HotGirl comes out into the room wearing a bathrobe, wet-haired, presumably just having showered.

Now something has clearly happened, but the dilemma for our hero is that he does not remember what happened. At situations like these, one is definitely required to say something, and one may potentially get into a lot of trouble if one admits he can't remember the previous night. On the other hand, one might also stand to gain a lot by playing this right.

What do you think happened to PastyFace and Hotgirl that night?

Read the answer here.