I look at this as a classic semi-bluff. The chips have to get in the middle somehow, and you possibly buy yourself a free look at the river by betting here.

If he comes at you on the turn you have a decision to make. Because of your read any bet on the turn likely means he has at least something, and you can decide whether or not to continue. Even if you end up folding, you're still a solid 3rd in chips five-handed with a 20+BB stack which is not a bad spot, eh?

Wee!