Cousins is a remake of a French movie that I've never seen. It came out in 1988 or 1989, somewhere in there, so by this time it's full of the kinds of fashions we like to laugh at nowadays. (Mullets and big hair, chiefly. I actually like the big hair, but the mullets, not so much.) It's directed, very well, by Joel Schumacher, a guy who isn't on anybody's list of great directors but whom I think tend to produce well-made films (from a technical standpoint).
In the movie, Ted Danson plays Larry, a dance teacher who is married to Tish (Sean Young, who never looked more beautiful). Isabella Rossellini plays Maria, who is married to Tom (William Petersen, ten years before he started following the evidence). In the opening scene, Larry's Uncle Phil marries Maria's mother, so Larry and Maria become cousins of some sort. They also meet in the reception hall after the reception has ended, because neither is sure where their respective spouses have disappeared to. Well, it turns out Tom and Tish have been doing the dirty (Tom turns out to be quite the philanderer), and after Larry and Maria realize this, they decide to pretend to be having their own affair in order to get back at them. It's a little joke...except they end up becoming close friends and then falling in love with one another. Hilarity ensues.
Of course, this is a remake of a French movie, so it all gets more complicated than that. Uncle Phil dies of a heart attack after being married for a couple of weeks, and then Larry's father Vince (Lloyd Bridges, who has most of the film's best lines) shows up and starts to woo Maria's mother. More hilarity ensues.
It's hard to honestly appraise a movie like this, since one must acknowledge that a state of affairs anywhere remotely resembling this one would result in all manner of emotional trauma for all concerned. (The movie does address, in passing, the effects of all this on Maria and Tom's daughter.) But the movie itself is awfully well-made, with chemistry positively dripping between virtually every couple it shows us, so I end up looking past a lot of that. Of course Danson and Rossellini have great chemistry; the movie wouldn't work at all if they didn't. But so do Danson and Young, and so do Rossellini and Petersen, and so do Young and Petersen. Heck, in a couple of scenes, even Danson and Petersen have good chemistry (although as rivals). It's also to the film's credit that its characters do bad things without being bad people. Even Petersen's Tom, the "cheating husband", is a fairly low-grade jerk who is genuinely hurt when he realizes that he's losing his wife. "Are you in love with him?" he asks; "If I am I'll get over it," she replies. "Yeah," he says, in return. "We were in love once, and we got over it." (It is kind of unfair the way the movie's finale leaves Tom in a limbo state; we get some idea that Tish will be just fine, but Tom's just tossed aside.)
Of course, this is a romantic comedy, so one must also judge it by if it makes one laugh, and it certainly makes me laugh. The Lloyd Bridges character has zinger after zinger ("At my age, you don't want to get too close to an open grave", "I'd rather have a case of the clap than a case of that wine."), and there's a hilarious scene set inside a wedding theme park where one of the cherubs is shown smoking behind a bush.
And the score is wonderful. Angelo Badalamenti writes a very French-sounding score (apropos, obviously), bound by two main themes: a love theme in waltz time (heard in a big way when Larry and Maria run away on Larry's motorcycle), and a simpler, beautiful theme for Maria. In a very nice touch, Maria's theme turns up throughout the film as diagetic music, played by street musicians as Larry and Maria wander by. The movie is also great looking, filmed in Vancouver, with lots of sweeping shots of that city's environs. Cousins is wonderful froth, if that's what you're looking for.