I think the river is a c/f as I don't see him turning his hands into a bluff here and he's likely only jamming better spades. His line makes me think he has a hand with showdown value or he would have folded much earlier so I think he would lean more towards checking back such hands. This of course is assuming no reads other than stats. I like the flop lead as it disguises your hand if you hit and you setup a big pot if you hit. If you bet on this 4 flush river I don't see him calling with worse like ever. Correct me if I'm wrong. C/f river gg sir wp.