Yes, he may let it roll of his back. If it does, he's testing you still. SOmetimes it takes time to come to one's senses.
If a child misbehaves and you send them to their room, they aren't gonig to to apologize any time soon. They ARE going to stew for a while.
You just keep putting the squeeze on him with more exposure. And do NOT go for romantic walks on the beach with him until he commits, you are just giving him a free pass. I don't expect him to cave immediately. He needs to come to realize how alone he will be if he leaves you. If his buddies are just gonna take him out for drinks when he's cheating on you, you need to talk to his buddies or something.