25NL: AK on BTN. Decent read or weak play?

[EN09]

fairly new to table with this being the 2nd orbit. i'm down a few chips from playing a 35s for a blind steal which was folded on the river. MP2 is 11/3/0 with 60 hands and SB seems to be a tad taggish.

Full Tilt Poker, $0.10/$0.25 NL Hold'em Cash Game, 9 Players
LegoPoker Hand History Converter

BB: $29.45
UTG: $20.50
UTG+1: $23.55
UTG+2: $25.70
MP1: $6.15
MP2: $27
CO: $9.55
Hero (BTN): $21.30
SB: $37.80

Pre-Flop: K[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/diamond.gif[/img] dealt to Hero (BTN)
4 folds, <font color="red">MP2 raises to $0.85</font>, CO folds, <font color="red">Hero raises to $1.75</font>, SB calls $1.65, BB folds, <font color="red">MP2 raises to $5.25</font>, Hero???
<font color="blue">raise more here initially? i was thinking $2.55 but did want action from MP2 and thought the SB would leave. surprise! </font>

now that i got action, i'm sure if i want it any longer. i'm thinking MP2 has big pair and i'm concerned about SB's preflop call.

EN