1/2 TT overcard on flop

[SvensHorse]

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

BB ($34.20)
UTG ($218.55)
Hero ($195.30)
CO ($189)
Button ($180)
SB ($216.60)

Preflop: Hero is MP with T[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/heart.gif[/img]. SB posts a blind of $1.
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $7</font>, <font color="#666666">1 fold</font>, Button calls $7, <font color="#666666">2 folds</font>.

Flop: ($17) J[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $13</font>, Button calls $13.

Turn: ($43) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $25</font>, Button calls $25.

River: ($93) 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets $50</font>, Hero folds.

Final Pot: $143

He is unknown. I really don't know, how to play this one.