Quoting Kimber-lily:" Bite him. "
Quoting ⚓ Sarah ⚓:" Have him bite into a piece of fruit like an apple, show him the bite marks and explain that thats what hes leaving on his brother and it hurts."
Quoting GrumpsMama.:" <blockquote><b>Quoting Stephanie Onyembi:</b>" I'm ready to put his fingers in his mouth and make him bite himself!"</blockquote> Worked for my LO. Like a charm"