50NL K9s vs flop C/R

[StarGrinder]

Here's a fun hand...

Villain is 23/14 over ~400 hands. I stacked him a few orbits earlier with a set vs his JJ on a K-high board. He's been fairly aggressive, opening a lot from various positions and taking down a ton of small pots. He has a high fold to 3bet% (86%) so his calling range OOP I imagine is narrow { pairs + AK }. I have a hard time folding here, since A) I think I've got the best hand and B) I'm sort of excluding <AK/KK from his range since we have blockers, hence the 3bet pre.

Insta-fold or snap-call?

$0.25/$0.50 No Limit Holdem - 9 Players

Stacks:
UTG ($141.60)
UTG+1 ($35.14)
MP1 ($43.28)
MP2 ($66.36)
MP3 ($31.60)
Hero ($104.33)
BTN ($45.95)
SB ($50.25)
BB ($42.75)

Pre-Flop: ($0.75, 9 players) Hero is CO
3 folds, MP2 raises to $1.50, MP3 folds , Hero raises to $4.50, 4 folds, MP2 calls $3.00

Flop: ($9.75, 2 players)
MP2 checks, Hero bets $6.50, MP2 raises to $15.00, Hero?