SB has $1000, MP2 has $400 and I cover. MP2 limps, I raise button with A♠ 3♠ to $20, SB calls.

Flop: J♥ T♦ 3♣ Pot $65 Checks around.

Turn: 6♠ Pot $65 Checks around.

River: A♣ Pot $65 SB checks, MP2 bets $50.

MP2 is fishy 55-60ish guy. Seen him try to bluff before a couple of times. Not sure if he's bluffing here. I doubt he's betting for thin value (like a J) but I think he may be bluffing.

Call/fold and why?