50NL; AK hand gets weird pre-flop

[Lego05]

UTG is complete unknown. Like 4 hands.
MP is also an unknown...like 4 or 5 hands.

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

UTG ($82.65)
MP ($25.25)
Hero ($51.25)
Button ($29.25)
SB ($102.20)
BB ($74.55)

Preflop: Hero is CO with K[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/spade.gif[/img].
UTG raises to $2, MP calls $2, Hero raises to $9, 3 folds, UTG calls $7, ]MP raises to $25.25</font>, Hero ???