Anybody, advice please!

So my son, he’s 1 year old, about to turn 2 in a few weeks, he has a habit of hitting his little cousin which is a few months younger then him, and any other little kid his age. He randomly hits, bites, grabs face hard to scratch and doesn’t like sharing toys sometimes.

My son is an only child, we live with my cousin and aunt and my cousin has a 1 year old child. My son is soooo affectionate. He still is. It’s only with little kids that he isn’t. Mind you, before we moved into my cousins house, my son was always so lovey dovey with his little cousin, he would kiss him and hug him and everything. He’s super affectionate but my cousins kid doesn’t like to be touched so he’ll push my son away and that gets him mad because he’s just trying to be affectionate. My aunt reccomends I hit my son to teach him not to be hitting and scratching and stuff. But I don’t agree. I feel like hitting him at this age is just gonna make him worse. How would you handle this situation? I feel like my son has changed a lot because my aunt and cousin are always telling him to leave his little cousin alone even when he’s just trying to hug him or even give him water and be helpful.