Toddler is kind of a jerk

How do you guys deal with your toddler misbehaving and being mean?? My 22 month old loves our dog, loves to lay on her like a pillow and tries to hug her, but she’s small (a Maltese/Poodle mix) and I always try to mediate so that he doesn’t squish her. However, he’s kind of a jerk to her at times. He throws things at her and has recently started trying to kick her. Naturally I am horrified, and then he thinks my reaction is funny so he does it again to get me to react. I don’t want to rehome her (she would just go to my parents, which wouldn’t help since he goes there three days a week while I work) and I obviously need to nip this in the bud so he doesn’t do it to someone else’ dog. She has nipped his fingers once or twice and I let her because he did deserve it, but he laughed so it obviously didn’t hurt; he thought she was playing like she does when they play with her toys together. Someone else’s dog or a bigger dog might actually really hurt him.

How do I teach him to be gentle? How do I discourage this behavior? Our dog is getting older and I don’t want her to be this crotchety old dog who hates kids so we have to put her away if people come over.