[private joker]

If you're going to call the river, I think you should check the turn behind. Giving a free card to him if you're ahead isn't too big a deal in this relatively small pot heads up. And I don't expect him to fold a better hand than yours to the turn bet, so it may be best to just take your own freebie. Use your position -- you got the card, you have a gutshot, a flush draw, and overs. And his bet on the river will be an induced bluff more often. As it is, I don't think he expects to fold a better hand than his with this river donk, so it looks like a value bet that doesn't want to give AK a free showdown.