Got greedy and put myself in a tough spot.

[SkippingGoat]

What's your play on the end?

Party Poker No-Limit Hold'em, $1 BB (6 max, 5 handed)

BB ($62.50)
UTG ($185.10)
MP ($131)
Hero ($53.25)
SB ($45.50)

Preflop: Hero is Button with A[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/diamond.gif[/img].
UTG calls $1, MP calls $1, Hero calls $1, SB folds, BB checks.

Flop: ($4.50) 2[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/diamond.gif[/img] <font color="blue">(4 players)</font>
BB checks, UTG checks, MP checks, <font color="CC3333">Hero bets $4</font>, BB folds, UTG folds, MP calls $4.

Checked to me on the button w/ top pair. Standard bet.

Turn: ($12.50) 3[img]/images/graemlins/club.gif[/img] <font color="blue">(2 players)</font>
MP checks, Hero checks.

Not too thrilled to have gotten a caller with my kicker so I decide against sticking more chips in the pot on the turn.

River: ($12.50) 3[img]/images/graemlins/heart.gif[/img] <font color="blue">(2 players)</font>
MP checks, <font color="CC3333">Hero bets $3</font>, <font color="CC3333">MP raises to $30</font>

I bet on the end because the paired 3's mercifully took my kicker out of play. I thought there was a good chance I'd get called by a king which is more or less what I put this guy on at this point. When he lashes out with a raise to $30 I of course instantly regretted the bet.

Read:
This guy had made some big bets in the past that hadn't been called so I don't know how to read him. He'd been pretty quiet for the last 50 or so hands.


Thoughts:
1) He could have read my $3 bet as weak (it was) and hoped to take the pot from me with any two cards.

2) He could also have an ace and potentially knock me out of the pot with the same hand that he's holding.

3) I'm somewhat sceptical that he has a 3. If he called the flop he would have had to have had 23, K3, or A3. I find it unlikely that he'd check to me twice, first with two pair, then with a boat, risking that I check behind on the river.

4) He could be slowplaying 22 (he probably would have raised AA, KK, or AK preflop).

I hate paying off big, out-of-line, bets on the end. But it's hard to fold here.

Thoughts?