<human>: Can you give me the gist of the text in a nutshell?

So basically my girlfriend and I go back to her place after enjoying a lovely meal at our local Korean restaurant. Having settled down to sleep for about twenty minutes, we begin to hear a scratching noise at the door. I ignore it for a minute or two but it continues, and eventually the handle slowly slides down and a figure topples through the doorway. The light spilling in from the hallway reveals a guy I know from school, an acquaintance who I haven't seen in around two years because he's been travelling the world. 

Though slightly surprising, this alone is not particularly shocking to us as he's a good friend of my girlfriend's housemate and is clearly just blind drunk and lost on his way to the bathroom. What is slightly more surprising, however, is what happens next. Clearly realising that he is in the wrong place but obviously incapable of doing anything about it, he proceeds to curl into a ball on the floor, pull down his pants and then piss for about a minute and a half, all over my girlfriends carpet. We then wake up her housemate, who drags him into the hallway where he carries on pissing for around another minute. He then tries to re-enter the room, naked from the waste down and shouting "it doesn't even matter!" and other, slightly less coherent phrases. I'm posting this as he has FINALLY gone to bed after much cajoling and I can't really sleep, partly because it was a hugely traumatic/hilarious experience and partly because I can't really wait for him to wake up tomorrow to the news that he pissed all over my girlfriend's apartment. As an added twist, he's been away so long that we're not even sure that he knows that me and her are going out or that he even saw me last night in his drunken, urine-spraying rage. Tomorrow is set to be fun.
<bot>: Guy I haven't seen for two years reintroduces himself by spraying urine all over my girlfriend's apartment in the middle of the night