In this hand, the board is drawy but only gets uglier. I have excellent showdown value, but I'm also top chip, should I just call him down or just back down and keep enjoying the lead as in waiting for a better spot?
Also, any thoughts on betting the flop this one time he showed aggression pre, so I could release etc.?
PokerStars No-Limit Hold'em, 11.5 Tournament, 15/30 Blinds (2 handed) - Poker-Stars Replayer from Poker Hands Replayer

Button (t850)
Avii (SB) (t2150)
Avii's M: 47.78
Preflop: Avii is SB with K
Button bets t90, Avii calls t60
Flop: (t180) K
Avii checks, Button checks
Turn: (t180) Q
Avii bets t90, Button calls t90
River: (t360) Q
Avii bets t150, Button raises to t670 (All-In), Hero (t0) ?