Well actually, there are a few hands he could have other than aces. He could be putting you on AK and have a pocket pair for himself that he felt was still ahead of your weak re-raise and assumed the ten missed you. He could have jacks, nines, queens, eights, etc..

If he had a flopped set, then you can thank that ace for falling.

Keep betting. If he calls the turn, get a cheap showdown. If he called your flop cbet with a naked ace, you will probably make your money back.