Betting The River - Flush On The Board

[Twitch1977]

Sorry if this is another random crappy hand post but I have no idea if I played this properly and was hoping for a few comments.

Paradise Poker 0.25/0.50 Hold'em (10 handed)

Preflop: Hero is SB with K[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/club.gif[/img].
<font color="666666">4 folds</font>, MP2 calls, MP3 calls, <font color="666666">2 folds</font>, <font color="CC3333">Hero raises</font>, <font color="666666">1 fold</font>, MP2 calls, MP3 calls.

Flop: (7 SB) 2[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/spade.gif[/img] <font color="blue">(3 players)</font>
<font color="CC3333">Hero bets</font>, MP2 calls, MP3 folds.

Turn: (4.50 BB) 3[img]/images/graemlins/spade.gif[/img] <font color="blue">(2 players)</font>
<font color="CC3333">Hero bets</font>, MP2 calls.

River: (6.50 BB) 8[img]/images/graemlins/spade.gif[/img] <font color="blue">(2 players)</font>
<font color="CC3333">Hero bets</font>, MP2 calls.

Final Pot: 8.50 BB

Now the reason I bet out the turn and the river was because I figured there was roughly a 50% chance my opponent held a spade. I thought betting out was a better solution because if I checked then he bet I'd be faced with trying to decide if he had a spade or was just trying to steal. If I got raised I was planning to fold.

Was it proper to play it like this or should I have just let it go?