What exactly did villian think he was beating when he called my flop bet? The bluff-raise preflop I can kinda see, but the flop?!?

Full Tilt Poker
No Limit Holdem Ring game
Blinds: $0.25/$0.50
6 players


Stack sizes:
Hero: $72
UTG+1: $50.75
CO: $49.25
Button: $17.40
SB: $24.25
BB: $186.80

Pre-flop: (6 players) Hero is UTG with
Hero raises to $2, UTG+1 folds, CO calls, Button raises to $3.5, 2 folds, Hero raises to $10, CO folds, Button calls.

Flop: ($22.75, 2 players)
Hero bets $10, Button calls all-in $9.4.
Uncalled bets: $0.6 returned to Hero.

Turn: ($41.55, 1 player + 1 all-in - Main pot: $41.55)


River: ($41.55, 1 player + 1 all-in - Main pot: $41.55)


Results:
Final pot: $41.55
Hero showed
Button showed

Villain sees a push, villain thinks "bluff" and calls irespective of his own hand.

has to be a big hand it has a king in it and its suited, good enough all in hand for any donk, you could have had k3 and he had you dominated.

Ps Thanks for the dontation, do come again.