Happiness is...

... spontaneously deciding to hold on tightly to the arm of one's unsuspecting fiance and thusly prevent him from leaving the couch as he'd planned; persisting with said endeavor until he opts to try in earnest to stand up and succeeds only in causing you both to topple over like dominos; giving up said arm only when continuing to hold on becomes impossible because one's stomach hurts too much from laughing.