Flopped Full House

[ReptileHouse]

It's metagame. If he flat calls the river after keeping the pot small the whole hand, the LAG will buy him drinks all night and hook him up with the hot waitress. Overall, it's +EV.

Seriously, though, OP, just bet. If he has an ace, he'll pay you off big time. If he doesn't, he won't be putting much money in there no matter what you do, so don't worry about it. Concentrate on extracting value from an ace. Just bet and build the pot.