Tough River Spot 25NL FTP

[SoulPower]

Not much history w/ BTN who was 22/11/1.6 over a few hundred hands. Not a standard open for me, but something I do occasionally.

Full Tilt Poker, $0.10/$0.25 NL Hold'em Cash Game, 6 Players
LegoPoker Hand History Converter

Hero (CO): $25.25
BTN: $55.15
SB: $33.60
BB: $61.40
UTG: $62.35
MP: $24.65

Pre-Flop: 4[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/heart.gif[/img] dealt to Hero (CO)
2 folds, <font color="red">Hero raises to $0.85</font>, BTN calls $0.85, SB folds, BB calls $0.60

Flop: ($2.65) A[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/spade.gif[/img] 4[img]/images/graemlins/diamond.gif[/img] (3 Players)
BB checks, Hero checks, BTN checks

Turn: ($2.65) 7[img]/images/graemlins/heart.gif[/img] (3 Players)
BB checks, <font color="red">Hero bets $1.75</font>, BTN calls $1.75, BB folds

River: ($6.15) J[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $3.75, BTN raises to $7.25, Hero ???</font>


guess it's an easy call, but what the hell do you minraise the river with that I beat that you played so passively on the first two streets?