Party Poker No-Limit Hold'em, 0.00 BB (7 handed) - Party-Poker Converter Tool from FlopTurnRiver.com

MP2 (16.20)
CO (4.11)
Hero (Button) (7.38)
SB (4.47)
BB (2.52)
UTG (4.60)
MP1 (5.00)

Preflop: Hero is Button with J A
CO calls 0.04, BB calls 0.04, 1 fold, Hero raises to 0.20, MP2 calls 0.18, 1 fold, CO calls 0.16, 1 fold

Flop: (0.68) 7 A 3 (4 players)
MP2 checks, CO checks, Hero bets 0.52, MP2 calls 0.52, CO calls 0.52

Turn: (2.24) K (4 players)
MP2 bets 0.48, CO calls 0.48, Hero calls 0.48

River: (3.68) 10 (4 players)
MP2 checks, CO checks, Hero bets 2.00, MP2 calls 2.00, 1 fold

Total pot: 7.68

I will not show you the results, because your head would explode, but what's your line here? Two calls on the flop... I'm really confused with the bet on the turn... Is he block betting? What is he block betting? When both checked on the river I was convinced I had the best hand and thought half the pot would get a call from a weaker ace, or maybe QQ or something.
What would you do on the turn? can you find a raise? To be honest, I would probably stack off here if one of them raised all-in, so I might as well raise it myself, right?