Folding Trips on the River, Settle an Argument

[Moozh]

I'm still very new to NL, but I thought this was a fairly safe fold. My brother disagrees.

Opponent here seems to be very loose/passive. Small sample of stats show him at 50/3 preflop (50ish hands so take with a grain of salt).

One thing I've noticed while playing the low limits is that pot-sized river bets seem to be very strong hands.

Fold or call? How's the rest of the hand?

Party Poker No-Limit Hold'em, $ Hero (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP ($22.85)
CO ($52.68)
Button ($8.85)
SB ($82.75)
Hero ($110.75)
UTG ($16.25)

Preflop: Hero is BB with K[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/club.gif[/img]. SB posts a blind of $0.25.
<font color="#666666">4 folds</font>, SB (poster) completes, <font color="#CC3333">Hero raises to $1.5</font>, SB calls $1.50.

Flop: ($4) K[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets $3</font>, SB calls $3.

Turn: ($10) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets $7</font>, SB calls $7.

River: ($24) 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $20</font>...