I think he was betting like he wanted you to raise him again.

I'm sure you had an aggressive image...he doesn't look like he's trying to showdown cheap, and he's not pushing you off the hand. It looks to me like he wants you to keep raising.

I'd play a set close to how he did there.

Maybe you had a good read, I don' t know, but even most suckers get off of that hand on your turn raise.