Guy issues

This guy I'm talking to doesn't like to message me after we have an argument. It's like I have to be the first to say something or we won't ever talk. It's like I wanna see how long it would take him to message me (if he ever would) but I can't stand not talking to him for a long period of time. It's been 2 days now and I don't know what to do. I wanna keep waiting to see if he would message me first but I can't. I need advice. The argument wasn't even that big but he still can never message me back after any argument. I was the one that was upset and I'm already over it. He should be too. So why won't he message me?? I know he still likes me but I feel like he's being a baby in all honestly.