Four Christmases is NOT about Christmas. I repeat, NOT about Christmas. It's just one of those movies that lures you in, thinking you're going to get some holiday cheer, only to crush you with a bad plot, no moral and a few stale jokes.
The movie is about a couple who is forced to see both of their divorced parents (on both sides) in one day, because there's bad fog in San Fran and they can't go to Fuiji. Sidenote: how often to flights get cancelled because of fog? I mean, SF is pretty foggy all the time, right? Aren't they
used to it by now? Anyway, these stupid people haven't seen their families on Christmas in three years, which is coincidentally, the same amount of time they've been together. If this was my family there would so be some shit-talking about the significant other who is stealing our brother/sister away. BTW, to my brothers: if you ever purposely missed Christmas, you wouldn't make it to the new year!
Anyway, at some point they think they don't know each other, but then somehow they realize that they want to be together forever and they DO want marriage and a family and blah blah blah. However, this realization seems to come from nowhere. Not from realizing their families are actually good and mean well (nope, come the next year they're still ignoring them). Not from the sentimentality attached to Christmas or even wanting to be together on Christmas. No, it's like Vince Vaughn doesn't want to be like his dad or something. Or maybe Reese Witherspoon realizes that families can pull it together? Or something like that? See, the problem here, is that the movie doesn't make this very clear. You keep waiting for a line or two to clue you in, but instead you're forced to create them in your head, filling in the blanks.
Vince Vaughn has some good laughs and he pretty much carries the damn thing. And next to Reese Witherspoon you realize (once again) that he's so tall! He kind of does this thing that reminds me of Billy Crystal, where he talks really fast, on-and-on, about nonsense and you're supposed to find it endearing. It works for a minute, but then I'd just rather watch When Harry Met Sally.
In the end, the movie has nothing to do with Christmas, with the exception that Christmas is the reason they have to go to all these places anyway. But it could've been Thanksgiving or Easter or any other family-centric holiday. You know it's not really a Christmas movie when they only Christmas song plays during the credits.