BB: 108 BB
UTG: 101 BB
MP: 108 BB
CO: 111 BB
BTN: 101 BB
Hero (SB): 100 BB

Hero posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has 5 6

fold, MP raises to 4 BB, CO calls 4 BB, fold, Hero calls 3.5 BB, fold

Flop: (13 BB, 3 players) 9 T 8
Hero checks, MP bets 10 BB, CO raises to 28 BB, fold, MP raises to 104 BB and is all-in, CO calls 76 BB

So, I'm not really sure where to go with this - I assume 65ss out of the small blind is probably a bit too loose, so I should probably be folding pre. However, am I supposed to be folding this flop?

The betting doesn't really smell like a straight, more like a shove with an overpair or set and a call with the same, or maybe it's a big flush draw. Against a set I've got something like 32% equity, and significantly higher than that versus overpairs (45%ish?)

Is folding here way too tight? Should I be shoving over a bet and a raise or is it safe to assume I'm drawing very thin?

The main reason I folded wasn't really because of the bet/call, it was because MP still had to act after I did, and I didn't really want to get squeezed for 28bb just to fold to a shove.

You don't have odds to call and you don't have fold equity to shove so fold 100%.

CO could definitely have a straight here and be trying to gii vs a set/overpair/strong draw.

Assign both villains a range, download equilab, calculate your pot odds and you should have your answer (fold).

3b or fold pre. 65s is far too low to be flatting a 4x raise out of the small blind. Postflop is standard.

Why wouldn't the betting feel like a straight? Some guy opens and QJs/67s are in his range. Some guy flats pre and raises flop and QJs/67s are in his range.

I'm folding PF. Squeezing might be okay.

Folding as played seems pretty standard.