flop line check,turn sizing?

multiway I'm leading turn about .40 and betting turn about 2/3 pot.
Def leading the turn for about 2/3 pot, dont want villain to set the pot size.

Given that we checked the flop, another way to think about this is to check/raise the button bet; play it like a re-steal and hope someone is reading your hand incorrectly.

On the other hand, if UTG is a whale flatting makes more sense to keep him in the pot...