Tim opens his mouth, rearing and ready to protest. He knows what 'let me think about it' means. It means this conversation won't be revisited. It means it certainly won't be revisited without a fight. It means Matt's going to say no without ever really considering it at all.

He doesn't want to fight either, but he's ready to. It's a stupid thing to fight about, all things considered. But he's opening his mouth to push harder when Matt beats him to it. Those hands steal around his waist, and Matt's speaking, changing the subject. Tim's not ready to. He wants to stay on topic.

His eyes narrow a little, even though Matt can't see it. "You're just tryin' to distract me."

That doesn't mean that it's not working. His curiosity is getting the better of him.