[Zag]

Unless you've seen him make "the move of honor" before, more often than could possibly be accounted for by him holding the nuts, then lay it down. You've put $22 in so far, so you have $108 left to risk. I think he will show you the stone cold nuts here more often than a missed draw or some other crapola. It is a little suspicious that he didn't check-raise on the turn, with any hand (even A7) that beats you, but I certainly have seen the mysterious call, then bet, with a big hand.

Very possibly he flopped a set with his big pair and decided to slowplay it. On the turn, he got afraid of the flush, then was afraid no longer on the river. I guess he could even have A7 and feared the flush on the turn. Since you have the absolutely tiniest full house possible on the board, there are too many hands that beat you. Fold it. It hurts, and you might be wrong, but fold it.

Your turn bet was fine. Bigger would have been fine, too -- yours was the lower limit of acceptible. Any lower, and you are just setting yourself up for a check-raise from a bigger set, without actually earning much at all from a draw.