I hate this spot. There seems to be a problem with every option.

Shoving the flop against a nit isn't likely to be great as he's probably not raising anything which stacks off worse than a set. You might have some fold equity but it won't be a lot.

Calling is obviously +EV, but on the turn your implied odds are reduced, and you're also OOP making it tougher to extract value if you bink. I'm not if saying we can donk the river solves this problem satisfactorily.

I'm playing this hand the exact same way against this player type for all the reasons Turlock said. If their hand sample were over 1k or more hands I might even fold the turn because I don't feel we're getting paid if we make our draw on the river.

Pre: Standard.

Flop: Definitely like C-betting this board here. When we get raised I wouldn't despise re-raising and getting it in with nut flush draw + overcard but my preference would be to flat here.

Turn: I probably just fold here now, we're not getting a great price and our draw is fairly obvious which will make it difficult to extract a lot of value when we hit. Raising as a bluff here is an option but against a seemingly nitty player this would be a mistake I feel.

River: Pretty interesting river card now. We're ahead of hands like KQ that have taken an aggressive line, we're ahead of all flush draws of which we don't expect villain to show up with here often, and we're still behind all two pair combos, again there should not be a massive amount of these out there. I think you can make an argument for a small donk bet here to try to get value from Kx type hands that are almost certainly checking river back, and then folding to a reraise.