QQ, all spade board, on the button

Party Poker, 10/20

MP1 raises, all fold to Hero on button. Q [img]/images/graemlins/diamond.gif[/img]Q [img]/images/graemlins/club.gif[/img]. I had been playing tight, MP1, SB and BB tight as well. Decide to just call. SB folds, BB calls.

Pot: 3bbs

Flop:

7 [img]/images/graemlins/spade.gif[/img] 8 [img]/images/graemlins/spade.gif[/img] 10 [img]/images/graemlins/spade.gif[/img]

BB checks, MP1 checks, I bet out, BB calls, MP1 2bets, I 3bet, BB reluctantly calls, MP1 calls.

Turn: A [img]/images/graemlins/diamond.gif[/img]

Check, Check, I bet out, BB waits a long time and calls, Hero calls after some deliberation as well

River: 6 [img]/images/graemlins/club.gif[/img]

BB checks, MP checks, Hero ____?