Flush draw makes second pair. What now?

[paperboyNC]

Reads: Button is a LAG: 67/20/1 (VPIP/PFR/AGGR)

Prima Poker 5/10 <font color="blue">(6 max, 6 handed)</font>

Hero is BB with Q/images/graemlins/diamond.gif 8/images/graemlins/diamond.gif
<font color="gray">3 folds</font>, Button calls, <font color="gray">SB folds</font>, Hero checks.

Flop: (2.5 SB) 4/images/graemlins/diamond.gif 6/images/graemlins/spade.gif 5/images/graemlins/diamond.gif <font color="blue">(2 players)</font>
<font color="red">Hero bets</font>, <font color="red">Button raises</font>, <font color="red">Hero 3-bets</font>, Button calls.

Turn: (4 BB) K/images/graemlins/club.gif <font color="blue">(2 players)</font>
<font color="red">Hero bets</font>, Button calls.

River: (6 BB) Q/images/graemlins/spade.gif
Hero?

I'm thinking bet/call or check/call. He played this hand so strangely though. He is aggressive pre-flop, yet just limps from the button.

[shant]

I wouldn't feel so good about bet/folding and bet/calling is kinda ugly so why not check/call because he's a LAG and he'll bet a wide range on the river.