SB is an aggressive regular who i have not played a lot of hands with. I've never seen him making any mistakes really. No numbers to offer since i don't have a HUD. 

Preflop, maybe it was a mistake to 3bet here, considering my relative position? BU is very loose passive, ideal situation is to get in a HU pot vs him.

 I can say fairly confidently when he pots the flop that his range is super strong, especially with 3 people behind him to act and W/ stack sizes what they are. I think a reasonable range looks like 2p+ w/ flush/straight redraw, and the made straight.  W/ that in mind i just called. If i was shallower i'm just getting it in on the flop. 

When the turn bricks and he goes all-in, i'm getting like 2.5/1 on a call, (131 to win 309.)

I plugged in some different hands to see what my equity is on the turn against what i think he plays this way:

nut straight w/ no redraws: 27%

Set no redraws: 30%

Set + flush redraw: 23%

Straight+ flush redraw: 26%

avg: 26.5% equity 

131/309= .424

EV: (.26 x 309) + (.74 x -131)= -16.6

 So what could I have done differently? I think that maybe i should have raised the flop, at which point i was closer to a flip. Even if he doesnt gii, it sets me up to have much better odds when the turn bricks. This logic may be flawed.

Any thoughts on any of this? I may have made mistakes in my math also.