I give villian a 15% 3bet range here, which it was at the time of the hand.

On the flop to simply things, i made him bet any 2 pair or better, and any fd.

that accounts for roughly 54% of his pre flop range.

Here, i assumed a passive opponent, betting only the nut flush.

And i assumed he will continue with any flush.. any set.. and straights vs my small bet.

that accounts for 62% of his hands, my bet needs to be profitable exactly 38%.. so i am breakeven with my bet. If the opponent is just slightly more aggressive, i think it becomes a clear profitable bet.

For example, i put in that he bets all nuts and second nuts, then he continues only in 51% of hands, given the assumptions mentioned above.

IF we assume he would have bet just the nut flush on the turn... he now has 48% of flushes in his range. Assuming he folds anything else, we have a super profitable bet.