KK, HU out of position vs a PFR when an Ace flops. Whats my play?

[balkii]

Party Poker 3/6 Hold'em (10 handed)

I have no read on my opponent in this hand. I am wondering what the default line in this situation is...

Preflop: balki is SB with K[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img]. CO posts a blind of $3.
UTG folds, UTG+1 raises, UTG+2 folds, MP1 folds, MP2 folds, MP3 folds, CO (poster) folds, Button folds, balki 3-bets, BB folds, UTG+1 calls.

Flop: (8 SB) A[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="blue">(2 players)</font>
balki bets, UTG+1 calls.

Turn: (5 BB) 7[img]/images/graemlins/heart.gif[/img] <font color="blue">(2 players)</font>
balki bets, UTG+1 calls.

River: (7 BB) 7[img]/images/graemlins/club.gif[/img] <font color="blue">(2 players)</font>
balki bets, UTG+1 calls.

Final Pot: 9 BB

Results in white below: <font color="white">
balki shows Kc Ks (two pair, kings and sevens).
UTG+1 shows Qs Ac (two pair, aces and sevens).
Outcome: UTG+1 wins 9 BB. </font>

[balkii]

OH maybe I just remembered. Check-call, check-call, bet. Is that right? It seems strange to check on the flop when I put the last bet in preflop...