100bb stacks, 6-handed

UTG pots to $.85, I call in BB w/KKT4ss

68 hands on utg and he's 35/16

Flop is Kd 7d 3d
c/c a half pot bet

Turn is Qx
c/c a half pot bet

River is Qx
I figure I'm repping a low flush pretty well and after a second barrel these guys usually just have it. Should I lead? I feel like I should because checking gives him a chance to check behind and he's unlikely to call a river c/r anyhow w/almost any flush since he doesn't look stupid. I've not been active and playing ~20/10.