When Trunks asks Mai to act as his girlfriend, both Pilaf and Shu thought he was referring to them.
Goten's reaction to Trunks having a girlfriend. "So cool..."
Then there's the "skit" they put up in attempt to steal a Dragon Ball. Trunks' dialogue sells it:
Trunks: I want to break up.
Shenron getting nervous when he hears that Beerus is there.
Gotenks' attempt to fight Beerus, which ends with Beerus literally giving him a spanking and making him apologize. Not only is this funny, but also rather satisfying considering how obnoxious Gotenks usually acts.
If you do the math based on the established timeline, both Bulma and Mai are lying about their age!
Which Oolong constantly points out towards Bulma, much to her chagrin.
Beerus eating Wasabi straight by mistake. He winds up bouncing around so much from the pain that he accidentally destroys a few planets/moons by plowing through them.