How do you play this hand? I wasn't sure what to do on the river. No reads really but I put MP on a flush draw by the way he was calling. I didn't think I could get away from the hand if I just checked to him so I figured I'd bet in case his flush was lower and if he raise I could fold, or in case I was wrong.

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) FTR converter on zerodivide.cx

Hero ($33.75)
UTG ($21.85)
MP ($24.50)
CO ($3.75)
Button ($25)
SB ($17.80)

Preflop: Hero is BB with 6, J.
UTG raises to $0.5, MP calls $0.50, 3 folds, Hero calls $0.25.

Flop: ($1.60) 3, 4, 8 (3 players)
Hero checks, UTG bets $0.25, MP calls $0.25, Hero calls $0.25.

Turn: ($2.35) 3 (3 players)
Hero checks, UTG bets $1, MP calls $1, Hero calls $1.

River: ($5.35) K (3 players)
Hero bets $3.5, UTG calls $3.50, MP raises to $10, Hero folds, UTG calls $6.50.

Final Pot: $28.85