So I have 2 year old twins and then also a baby and this so sounds like my twins😂it’s totally normal and I think you’re handling it just fine. Just because you’re not handling it the way a different family member would doesn’t mean anything, this is as you said a normal phase he needs to go through and you have to do what you feel is best to help him through that. Something different works for every kid and you know him and what he needs better than anyone. Something I found that works or my twins is telling them that if they want to use their hands it’s only for hugs, knucks (knuckles) or high fives, they love doing all those things and mentioning them makes them stop hitting and want to do one of those instead😂they also laugh when we have a bigger reaction to their negative behaviors so when that gets out of control and we can’t redirect them from doing whatever it is we’ve started putting them in timeout and they’re learning that they don’t want that lol
So maybe there's something that those family members are doing behind closed doors that he doesn't like. My daughter is just now warming up to my sister because my sister would irritate the 💩 out of her. If my daughter said no hugs, my sister would chase her and swoop her up and kiss her all over, forcing it on her while she kicked and screamed and hitting, then get mad because she got hit. That got tiring so I put a stop to that. Or my daughter acts differently around my mother, she's a bit of a narc. I have actually had to separate our families in one house due to the sneaky and rude stuff going on (we live with a total of 9 people, some days 11!). I limit the amount of times I need help from them with my daughter and try to make it on my own the best I can. I say you deal with your son how you want, if he doesn't want love and affection, then he doesn't want it. Plain and simple. You can ask, if he says no, then no. What's so wrong with not wanting love and affection all the time anyways?
Even as an adult I want my space and can be touched out or I may be sensitive to certain touches, just like toddlers. He may also see how much everyone looks to you for discipline or a response and that may make him confused. My daughter is very similar. She even doesn't want Daddy most nights. It's all about momma unless I'm out the room and she acts nicer and is much more appropriate with her behavior. Weird but that's just how it is it seems. And that ok because that just means we as mothers have done a great job bonding with our children. Kids test those who seem weak in authority as well, keep that in mind. They should step up like you say, it'll take some time but everything should work out. I unfortunately have no creative ideas but I am open to some 😊
And just let your family know that if they don't step up he's not going to learn to respect them, and of course you can back them up occasionally
My oldest is kind of like that as well. He doesn’t hit his brother but most times it’s difficult for him to share with his brother. He would give him a toy and snatch it away as quickly as he gave it to him and he screams “no“ at him. Or when he wants space he doesn’t even like his little brother just sitting near him. But then there are times when he would get up and hug his brother just cause. I don’t really have a good solution. He’s in his terrible two stage where he cries and throws a fit over the smallest things and my mom tells me it’ll be okay it’s just a phase that babies go through. So right now I’m sort of just waiting it out lol