Set of 7's

[nutstoyou]

I'm at work so I don't have the hand history, but I'm only interested in the flop, so the hand history is fairly simple.

25NL on PokerStars with 6 players. No reads on any players because I just sit down at the table.

I'm dealt two red 7's in MP. UTG limps in. I raise to $1, the button calls, UTG calls.

Flop is Q, 10, 7 all spades. UTG is short stacked and goes all-in for $4.25. I call the $4.25 (my stack is around $25). Button, whose stack is also around $25 then raises and goes all-in, making it $21.75 for me to call

What's my play?