Personally I'd be raising the flop to stack off worse flushes, sets and over pairs with a spade. I'd have made it $2.25 and call a shove. As played I don't fold the river, they can be betting worse flushes here.

I'd need some kind of read or note to make a hero fold on the river.

Tbh I was thinking about my flop raising range on this situation.I would probably call with all my sets,two pairs etc.I couldn't find many bluffs in my range when fish is still in the pot.Raising flop should be good to GII OTF against worse made hands.Turn was close also but it would be better to jam in OTT I assume before another action killer card falls.I would call turn bet with pair+fd type of hands.His raising range from MP shouldn't have many full houses given the action but yet he might have other flushes that probably will play same way.

Pre flop I would be using this as part of my bluff range.I'm not keen on calling with no other callers in the pot yet.

With the nuts and a lot of action killer turns I'm never slow playing on this flop. We want to charge sets to fill up and hopefully get it in before a spade rolls off and you lose your action.

As played I'm calling the river because it's believable he can bet a worse flush for value.