Was my play completely obvious to this opponent?

[salloch]

Villian called my river bet *very* quickly and turned over a very vulnerable (but winning) hand. Was my line totally obvious? No great reads on either player.

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) converter

Button ($60.20)
Hero ($61.95)
BB ($16.70)
UTG ($51.50)
UTG+1 ($55.30)
MP1 ($21.15)
MP2 ($37.60)
MP3 ($14)
CO ($53.10)

Preflop: Hero is SB with A[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/spade.gif[/img].
UTG calls $0.50, <font color="#666666">2 folds</font>, MP2 calls $0.50, <font color="#666666">2 folds</font>, Button calls $0.50, Hero completes, BB checks.

Flop: ($2.50) 5[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets $2</font>, BB folds, UTG calls $2, <font color="#CC3333">MP2 raises to $4</font>, Button folds, Hero calls $2, UTG calls $2.

I thought that BB caught a piece and that MP2 might be on a flush draw. I pretty much ignored the min raise. (mistake?)

Turn: ($14.50) 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets $15</font>, UTG folds, MP2 calls $15.

After the call, I thought I was in trouble.

River: ($44.50) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $42.45 (All-In)</font>, MP2 calls $18.10 (All-In).

I knew if I got called, I would loose, but with the scary board, and me never having shown weakness, I thought there was a decent chance he would fold to a $18 bet.

Was this a horrible bluff on my part? I have the feeling villian saw right through it.

Final Pot: $105.05