A2 in the bb

[Snupoker]

Im the BB with 26k in chips, MP has 15k, Button is the other big stack with 25k. Get A2 with blinds of 500/1000. 18 left, pay top 12.

MP and button Limp, SB folds, I check. Flop Comes 3-4-5 rainbow. I check, MP bets 1.5k, Button raises to 5k, I jam it. MP folds, button calls with 6-7. Is there anyway I can get away from this hand. If I lead, MP either just calls or plain folds and LP raises me. It makes no sense for me to fold here as the ONLY hand that beats me is 6-7. If I call and the turn bricks, can I really check/fold. I dont care about cashing, but want to win this. Im hoping this is just crap luck, but if anyone can give me a better line. Please tell.