Help with cousin picking on my kid

So long story short my cousin passed away but her fiancé and son still come to our family dinner every Sunday. Let’s call my cousin’s kid Tom. So Tom lost his mom last April a couple weeks after turning 3. The kid is very stubborn and his dad doesn’t really do a whole lot of parenting. My aunt takes care of Tom quite a bit and is that mother figure in his life. Well every Sunday dinner Tom chucks toys, punches my kid in the face, pushes him and so on. But no one does anything except me! Tom’s dad is very non confrontational and prefers to just tell his kid to say sorry and his kid usually says no and doesn’t do anything after that. My son currently has a broken collarbone and can’t be taking stuff like that rn but yet I’m the only one to really tell Tom what he is doing isn’t nice. My kid is a year younger and a lot smaller in size to Tom. He also threw a toy at my 8M old daughters head todaySo it’s hard when no one steps in to parent Tom. Also if I usually say something to the family about it the excuse is his mother died. Which yes I understand is sad and awful. I would never wish that upon any kid. I was very close with my cousin as well and lots of us miss her dearly.

What would you guys do in this situation? I’m very close to my family so I don’t want to just stop going to Sunday dinner all together but this kid has no parental structure allowing him to pretty much do whatever he wants . 🫤