Once...Twice....Three times a donkey?

[Qygoth]

What the heck do you donk bet 3 times with and don't re-raise? Some people just amaze me.

Have you seen this guy bluff a lot at pots before? Or bet out small holdings vs a PFR? I'm thinking I'm just calling the river donk. I'm guessing he has some of the flop, real question is how little. K, flush or 3 all beat you. I'm hoping he's betting an 8 or Ace of clubs/8.