$4/180 - Final heads up hand

[True North]

Oof. River is just total spewage. You have a little value with the pair of sixes, so you need to check behind. With a CR by villain, you're not pot-committed, and it's a pretty clear fold.

Had you been betting a lot when checked to on later streets? If so, given the play on the flop and turn, there's a pretty good reason to think he was trapping. If this is a bluff, it's a really bizarre one.