[Dommer]

Interesting hand...

I don't see him checking the flop with a set or AK if hes aggressive, and I don't see him checking behind with those hands or a flush on the river.

I'm guessing he thought you were weak and was hoping he could make you fold by representing an A or a flush, in which case you played good. But that's a very strange bluff by him...

You are out of position which makes a continuation bet very awkward if you get called, so I think checking the flop is fine.

You can't really value bet the river, you'd have to call the push.

Tough hand, I really don't see how else to play it. It seems like every line has it's drawbacks. Your hands are tied by the stack sizes and the flush on the board; value betting isn't comfortable, getting all-in isn't comfortable, and neither is folding.