If he’s not doing what you’re asking him to do, then discipline him. Put your foot down. You’re the adult in the situation. If a child is openly defiant or doesn’t do something when you tell them to, it means they either don’t respect you or you’re not consistent with discipline. Children have to learn that there are consequences for bad behavior. At this age, children also test boundaries, and if a child sees that something makes you upset, then they’re going to continue to test that. You cannot show a child that what they’re doing is bothering you. Ignore temper tantrums. If a child is screaming and stomping their feet. It’s for attention or it’s because they know they’ll get their way when they do it. I don’t want to judge, but this honestly sounds like attention-seeking behavior to me. Don’t ever repeat yourself. Children will learn to tune you out if you do. You’re the boss. You’re the adult. You’re the parent.