First hand in game. No reads. No HUD.

$50 effective stack. 4 players.

Hero UTG with Kc Ks 6c 6s

Hero raises to $1.75. Button, SB, and BB all call.

Flop: ($7.00)(4 players)   Ah 7c 6d

Chk, Chk, Hero bets $5.25. Button raises to $22.75. Sb folds. Bb raises all in for $48.25.

Hero????

I am pretty sure this is a fold, but maybe not? (Kind of why I am posting, hint, hint.)