Sex (or in some cases, a relationship) that starts out slow, or sometimes barely at all, usually with a chick who is very shy. But once you get her started (uncorked), she lets loose and the longer it goes, the better it will be, with time.
Luke: "Hey dude, you remember that chick from the library I hooked up with?"
Zeke: "Yeah, what about her? How did that go?"
Luke: "You wouldn't believe it! It was the best wine sex I've ever had!"