NL50; Two pairs on paired flop.. What to do?

[vovans]

Hello there! Its my first post [img]/images/graemlins/smile.gif[/img]

BB - unkonown. Played a few hands on this table.

Prima Poker skin
No Limit Holdem Ring game
Blinds: $0.25/$0.50
6 players
Converter

Pre-flop: (6 players) Hero is CO with A[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/heart.gif[/img]
2 folds, <font color="#cc0000">Hero raises to $2</font>, Button calls, SB folds, BB calls.

Flop: 7[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/spade.gif[/img] ($6.25, 3 players)
BB checks, <font color="#cc0000">Hero bets $4.5</font>, Button calls, <font color="#cc0000">BB raises to $12.1</font>, <font color="#cc0000">Hero ???</font>

Calling I think is bad move. Maybe all-in?