What would you do in this situation?

Okay so my sons dad has only been in his life for a year, after nearly two years of not being around at all. My son is four. Me and his girlfriend happen to have become close friends so I’m hanging around quite a bit and we talk a lot.

The other day while I was there my son, me, her, and my ex all went for ice cream. Everytime my son would get excited over something for example when the worker started making milkshakes in the ice cream machine, he would get so tickled over it. My ex would take him try to go off an sit somewhere and tell him to stop. Or when my son was standing there trying to look at all the toppings through the glass cabinet thing they were in he would yank him away from it and tell him to quit.

All day long he was threatening to “bust my sons ass” over stupid, small things.

Now I did tell him he could whoop him if needed but what I meant by that was if he was just being absolutely terrible and doing something extremely bad and wrong. Not over him being a kid.

Also for the next story I’m letting you know beforehand my ex lives at home with his Dad and his dad’s girlfriend.

For some time this summer my exes girlfriend was coming to get him and they would spend the day just my son and her.

Well one day they were over there and my exes Dad was at home. My son was apparently being mean to him, idk exactly what he was doing, but he got up and took my son into his bedroom and started whooping him and then left him in there by himself and told him not to come out until he was ready to mind.

I am NOT okay with anyone that’s not his parent whooping him, I live with my mom and stepdad and they don’t touch him, heck I barely ever whoop him myself!

It doesn’t sit right with me at all and I want to talk to him about it but I don’t want to tell him that I know about that incident because then he’ll know his girlfriend told me and it will start an argument and idk if he even knows about that incident.

I already told him when we started this (and it took me a very long time to trust my ex enough to start letting my son go over there by himself without me and even now I only like it because I know his girlfriend is there) that if there was ONE thing that I didn’t like I would stop these visits that I’m not messing around. After everything he put me through in the past I’m DONE. I don’t want my son to stop going but I also don’t want him being treated wrong over there by people he barely knows! His dad only gets him like once a month or so.

So I think I’m going tell him that if he’s just going to whoop him over anything and everything that I’m not okay with it and I don’t want him whooping him anymore, and that I 10000% don’t want anybody else to put their hands on my child I don’t care who they are. And that if it happens again my son will not be going back over there.

He can do time out like I do, talk to him, etc.

I’m just scared to say anything because he likes to take things, twist them around and start an argument but this is my child and I don’t want him being mistreated.

Sometimes I wish I would’ve never agreed to this. But I just want my son to have his other family but not if it’s going to be like this.

Also I’m his only legal guardian, by law I don’t have to send him over there or let them see him at all but I choose to because I knew how it felt to never have my dad around or never be able to see my dads side of the family.