Had a weird-ass dream and I'm freaked out.

I blame video games.

Mine were/sometimes still are frequent and horrid (I'd rather not type them, but just take my word for it they're worse), but I doubt a single weird one's a sign of anything. If you were having them nearly every night, and they were severe enough to affect you while you were awake/keep you from being able to sleep, that's when you need to be concerned. I'd write this off as you having some sort of subconscious stress (doesn't even have to have any relation to what's going on in the dream) and wouldn't worry. :)

No pee in your bed. Sure...

You're giving this too much thought. Dreams are just a manifestation of one's subconscious and often include past experiences of any kind, regardless of time. You played Postal so there you have it. It doesn't mean anything. I once dreamed I was still in high-school and zombies were invading it. After which I found a katana on the wall, cased in glass with the sign "In case of emergency break glass". I'll give you 3 guesses what I did next. So, see? Everybody has weird dreams.

very... detailed

lol thanks for all the answers, people. I guess I won't give it much more thought. I was freaking out because it was just weird, peeing in someone's mouth. That's the only part that I got thinking about.

As others said, dreams happen to be weird sometimes. Maybe you should have peed before going to sleep :D
Physical discomfort often carries over to dreams, so if you're very thirsty, you might dream of drowning or drinking sand or something, if you really need to pee, you might dream about peeing in the most absurd and inappropriate places. Just my somewhat late two cents.

sounds more like postal to me

I see a lot of fucked up dreams too. I used to wake up freaked out confused sweat etc but after some hours I would almost forget it and i was better. Im kinda used to it now and dont freak out, in matter of fact its happening the opposite. Sometimes I manage to interact on my dream but the most of the times i wake up the moment i try to do it.
It was just a dream...

was it?!