[xenion]

grunch

I wouldn't ch/r on the flop. I don't know what kind of monster you could represent with a flop like that when you didnn't raise preflop. Even if MP1 is on flush draw I would guess UTG+1 has a pocket pair of overcards possibly 2 of your 6 outs. It just doesn't seem the right time to be aggressive.

I might even ch/fold on the turn being convinced that UTG has a made hand after his 3 bet on the flop.

I would bet/fold the river.