This movie sucks. It isn't just unfunny, it actually made me mad how bad this movie is.
Vince Vaughn is usually good. Even though I didn't like Fred Claus very much, Vince Vaughn made me laugh. Not in Four Chrismases. I don't think he made me laugh once. He just annoyed me. And Reese Witherspoon is not funny at all. She has never been funny. Legally Blonde might have been funny (I can't remember for sure), but if it was funny, it was the writing and the people around her. But she is not funny.
One big problem with the movie is that they have no chemistry together. Brandon Routh and Kate Bosworth had more chemistry in Superman Returns than they do here. In order for a movie like this to work, you have to want the leads to end up together. There is a point in the movie (as formula dictates) where they have a fight and they separate for 10 minutes or so. I was hoping they wouldn't get back together. I was thinking "yes, you're not right for each other. Move on."
Another problem I had was that this is a bad idea for a movie. Four sets of in-laws in one movie (well, technically not in-laws, because they aren't married, but same difference). One reason Meet the Parents and Meet the Fockers worked so well is you had a whole movie to establish the parents' characters and get to like them. But four different parents? I don't see how you could make that work. Not as a serious romantic comedy.
Here's another problem: they've been dating for a few years, and their parents live within an hour's drive from each other, yet they've never met each other's parents? I can believe that they never spend Christmas with them, but in 3 years, never a dinner? Kate's sister (Kristin Chenoweth) has a baby. When her baby was born, Kate and Brad didn't even go see the baby? Maybe they live out of state and just flew back for Christmas, but this is never mentioned. This could have been fixed so easily. If it was written so they had only been dating for 3 - 6 months, it would make sense that both Kate and Brad have been hesitant about introducing their significant other to their parents.
The only person that made me laugh was Jon Favreau. The half a star in my review is just for him. Actually, that's not fair. Sissy Spacek made me laugh too. The scene where they play Taboo is the only time during this movie I didn't want to open a vain.