Shinae not just slaps, but punches Kiel'ndia out of a hysterical fit over the demon-transformation of Naal'suul.
Much earlier, Nihi'liir slaps Faen after she starts to panic on the way to the tainting ceremony and quickly finds out why this is not a good idea when dealing with The Empath who has Power Incontinence. She loses an arm while their teacher, who steps in to break it up, winds up brain dead.
While everyone is understandably wallowing in despair after the events of [S]GAMEOVER, Terezi, who at this point is bleeding to death, flies over to John, crashes in front of him, walks out of the crater and still has enough strength to headbutt him hard enough to break his nose.
Laura in Collar 6 administers a much-needed love tap to her Mistress when Sixx indulges in a bit of Wangsting, followed by an equally well-deserved verbal slap. It ultimately comes across as heartwarming.
Performed by DiDi on Zii when she considers sex (then a threesome) as a way of apologizing for breaking Gary's rare Transformer toy....which was just as well; it wasn't really broken, it was designed to pop back together though they had no way of knowing that at the time.
In Mokepon, Atticus is just recovering from nearly being shot when he and Dragonthing run into a giant swarm of angry Bug Pokémon. Dragonthing has to bite Atty to knock him out of his Heroic BSOD before they high-tail it.