good stuff. couple of things.
1. grammar/syntax/whatever. As written, the sentence starting with "They were P.J..." doesn't make sense because you get caught up in describing PJ and forget to tell who the rest are till later. I'd do just a little rearranging. something like, "They were PJ, his wife Kat, Andy and Andy's girlfriend whose name I could never hear," and go from there to the descriptions.
2. you set up the scene well, but you don't give us anything about what this girl looks like, just that she was pretty and in love... her story is interesting, so it keeps us going, but... i think you can make this even stronger than it already is by being as descriptive as possible.
oh yeah, one more thing... PBR is pretty well known, so you don't have to explain what it is, but... i dunno, it just sticks out in that first sentence. doesn't fit well. later, when you mention the round of shots, you don't have to tell us it's tequila because PJ refused the lime. that's brilliant. I would personally replace PBR with "a cheap domestic" or something of that ilk, just in case your readers are in miller country or something ;)
anyway, that's it. hope it's helpful.