My wife and I will have been married for 10 years this coming May and sometime later this year we'll pass the point where we've been together longer than we had been not together (we're both turning 34 this year and started dating when we were 17).
I cringe a bit to think of all the "pet names" and mushy stuff we said to each other when we were kids. But then again, that's the stuff we've built our great marriage on so I won't say too much bad about it.
One little affectation of affection that we developed came from the movie "Beautiful Girls" where Uma Thurman tells some dude (and I'm paraphrasing most of this), "I just want a guy who will be there every night to say, 'Goodnight sweet girl.'" And just about every night when we finally curl up to go to sleep I tell her "goodnight sweet girl". Mushy and stupid? Yeah. But that's what love is all about, right?
Also I've noticed that we fart on each other a lot more than we did in the old days.