Although Pleasure Island does have some dance clubs, there are some other places that you may enjoy-- Do you enjoy comedy clubs? The Comedy Warehouse is a comedy club that is in "Improv" style-- it's pretty fun (and a little more "family-ish" then some other improv comedy clubs I've been to). There's also a club called the Adventurer's Club, which is really unique to Disney-- the CMs at the club are all "characters" and they put on shows and interact with all of the guests there-- I really like it!
If those don't sound lke something you would like, maybe you guys can get away from the kids for either a quiet dinner at one of the more "adult" restaurants, or even see a performance of Cirque du Soleil??