chin smack
Using the top part of your hand to smack your girlfriend under the chin because she said something obvious.
Her: it's so hot out here I wish I would have put on sunscreen!
Him: I warned you before we left the house you should have put some on and you didn't listen. You deserve chin smacks. (Smack smack smack)
Him: I warned you before we left the house you should have put some on and you didn't listen. You deserve chin smacks. (Smack smack smack)