Overplayed overpair

[twolf]

I've been at this table for two orbits and this opponent seems really loose and passive but has been caught bluffing one time.

Party Poker No-Limit Hold'em, $0.50 BB (10 handed)

UTG ($53.49)
UTG+1 ($81.70)
UTG+2 ($65.65)
MP1 ($23.35)
MP2 ($6.25)
MP3 ($43.10)
Hero ($27.65)
Button ($27.10)
SB ($28)
BB ($40.35)

Preflop: Hero is CO with J/images/graemlins/spade.gif, J/images/graemlins/diamond.gif.
UTG folds, UTG+1 folds, UTG+2 folds, MP1 folds, MP2 folds, MP3 folds, Hero raises to $1.5, Button calls $1.50, SB folds, BB folds.

Flop: ($3.75) 6/images/graemlins/club.gif, 4/images/graemlins/heart.gif, T/images/graemlins/club.gif <font color="blue">(2 players) </font>
Hero bets $3, Button raises to $15, Hero raises to $26.15 (All-In), Button calls $10.60 (All-In).

What should I do different?