i have the nut flush.... river action

[jfresh]

opponent is 57/7/1.5 though 150 hands

Party Poker 10/20 Hold'em (6 max, 5 handed) FTR converter on zerodivide.cx

Preflop: Hero is MP with 6[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, Button calls, SB calls, BB calls.

Flop: (8 SB) 4[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, BB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">Button raises</font>, SB folds, BB calls, Hero calls.

Turn: (7 BB) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, Hero checks, <font color="#CC3333">Button bets</font>, BB calls, <font color="#CC3333">Hero raises</font>, Button folds, BB calls.

River: (12 BB) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">BB raises</font>, Hero....?

BB has the Kh? doesn't seem like he'd checkraise with that. but what in the world kind of full house could he have? a horribly slowplayed 44?

should i 3bet or call? or is this an easy decision....