$100 PLO on UB, 6max. Opponent is tricky and aggressive. One earlier hand that is relevant here: I flop nut straight on AQJ board with two hearts and pot on flop and turn. River is a Kh, and villain leads for the pot ($30 or so). I fold, and villain shows QQ, no hearts. He's shown some more bluffs like this. My stack in this hand is $170, he covers.

I raise in MP with JJQKr. Villain calls in SB, BB comes along, rest fold

Flop: J74, two hearts.
I pot, villain calls.
Turn: offsuit Q. Check, pot, call
River: offsuit 6. Villain pots for $100.

Now, did he 1) use his previous play in a small pot to set me up in a big pot? Or is he still thinking that 2) I'm the kind of opponent who folds to a big river bet when a scarecard hits? Or is he thinking that I'll fold precisely because even though I know he bluffs often I'm reasoning along the lines of 1)?

Does your decision change if a heart hits instead of the straight?

Good LAGs have draws, usually. They don't always hit them, but they make it seem like they do. Calling with air, just to (possibly) spew some more on the river is going to be a bad play a great percentage of the time.

This guy just suffered from a serious case of FPS.