10/20 KK weird spot

[BalugaWhale]

villain is bardstrijker or something like that, if you know him... not a great read but seems to play straightforwardish
we are 150 bb deep
I raise KK utg, he calls OTB, flop is QJ3r. pot is 167, i bet 120, he calls. Turn is a J. Pot is 407. I check, he bets 300, I call. River is a 9. I check, he bets 500 into 1000.

how's my line? and what do I do now?

i think leading riv is very viable, but i'm not sure how often i get looked up by worse hands (besides AQ which would probably bet the river if I checked again anyway).