We let our cat sleep with us. He's family, but man he is one heck of a bed hog. Also he's incredibly jealous of my wife. He's always been a little more attached to me, although he's warmed up to her a lot more lately. Still when it comes down to it, if I'm in bed before her he'll do things like sleep on her pillow and try to usurp her spot in the bed. It's very very cute.
One thing I've noticed that I'll broach rather carefully is that he tends to get upset if he's kept out of the room for any reason while we're in there. Obviously there's certain times as a couple where you need privacy, and he will sit outside the door sometimes and just meow obnoxiously. It's a little weird to be honest. Cats are strange creatures.