LAG limp/raises Preflop question

[@bsolute_luck]

UTG is a LAG, MP LP, BB standard PRF aggression (low hand sample).

1/2 6-max
Hero SB A[img]/images/graemlins/diamond.gif[/img]J[img]/images/graemlins/club.gif[/img]

Preflop LAG calls, MP calls, 1 fold, Button calls, Hero calls, <font color="red">BB raises, LAG 3-bets</font>, MP calls, Button folds, <font color="blue">Hero...???</font>

FWIW: i'm more concerned with BB behind me. if you're calling here, what are you doing if he caps it 'cause that's what i'm wondering here?