[Pog0]

If your pair is second pair or a PP better than second pair, why not just bet the river? He'll call his aces, sure, but he'll also call all other pairs. If you check, he'll probably only bet his aces and I don't like folding here very much.

Your check screams "I don't have an ace!" and even the fish may try to bluff you with his 23s that missed on the river, so I don't know how right check/folding can be here. However, he's more likely to have a mediocre hand and check behind (or call if bet to) than he is to have a missed draw and bluff if checked to.

Bet/fold please (if your pair => 2nd pair.