How could I have played this better?

This guy outplayed me, but are there any clues to what he was holding? Obviously I didn't see any. How could I have played this better?

PokerRoom No-Limit Hold'em, $0.25 BB (10 handed) FTR converter on zerodivide.cx

saw flop|saw showdown

fletchmuy($9.10)
BB ($18.20)
UTG ($17.55)
UTG+1 ($34.95)
UTG+2 ($24.80)
MP1 ($11.75)
MP2 ($47.30)
MP3 ($16.30)
CO ($25)
Button ($14.05)

Preflop: fletchmuy is SB with 9,T. CO posts a blind of $0.25.
UTG calls $0.25, 5 folds, CO (poster) checks, 1 fold, fletchmuy calls $0.10, BB checks.

Flop: ($0.85) J, Q, 3 (4 players)
fletchmuy bets $0.25, BB folds, UTG raises to $0.5, CO calls $0.50, fletchmuy calls $0.25.

Turn: ($2.35) 8 (3 players)
fletchmuy checks, UTG bets $0.25, CO calls $0.25, fletchmuy raises to $0.75, UTG calls $0.25.

River: ($3.60) T (3 players)
fletchmuy bets $1, UTG calls $1, CO raises to $3, fletchmuy calls $2, UTG folds.

Final Pot: $10.60

Results in white below:
fletchmuy doesn't show.
CO has Ah Ks (straight, ace high).
Outcome: CO wins $10.60.

a stronger raise on the turn is merited. you made it .75 in a $2.60 pot.

Waaaay stronger.

Heavier bet on the flop - at these stakes, you made it too juicy for him to chase the straight... plus he probably felt if he hit an A or a K he was taking down the pot (of course we know thats not true, but he thought so). He caught his card on the river and made you pay for it.

Not as much outplayed as much as you letting it happen with the weak turn bet. At the turn, you have the best hand, but it is vunerable - PROTECT IT. Even if it means a smaller pot by taking it down there, its better than losing money on it.

Thanks for the advice, everybody.