$50 NLHE 6-max: 3B Pot / 77 vs Small flop bet

Villain is unknown

BTN: $50 (100 bb)
SB: $101.84 (203.7 bb)
BB: $114.62 (229.2 bb)
UTG: $54.33 (108.7 bb)
Hero (MP): $57.11 (114.2 bb)
CO: $50.74 (101.5 bb)

Preflop: Hero is MP with
UTG folds, Hero raises to $1.50, CO calls $1.50, 2 folds, BB raises to $4.50, Hero calls $3, CO folds

Flop: ($10.75) (2 players)
BB bets $3.50, Hero ??

Normally I fold here, given the small bet I'm indifferent to calling or folding. If we do call we'll have to call similarly sized turn bets on non A or K turns.

I fold pre?

Are you planning to bluff raise turns that are a 7, 6, 9, or 4? If so, I don't hate the float given the bet size.

I would fold pre, or if he is a maniac 4bet with the intention of staking off. The way this hand played I think you should call here and call most turn bets as well, but fold to a 3rd barrel.

I know fish make these small bets on flop and turn at these stakes when they have either overs or draws, but since villain is unknown and deep stack I think we should assume he is good and fold preflop.

Meh tiny 3bet, likely fishy player, the calls just under 20 to 1, CO rarely 4bets, position, relatively strong pocketpair. I wouldn't get in the habit of calling squeezes with this hand but the tiny sizing makes it good for me here.

Pre is okay, just not if you're going to then fold on that flop for tree fiddy. But then, don't call flop if the plan is never to show any aggression without binking a set. So, I'd be calling with the intention of bluff raising certain turns (not the cards the c9 person mentions) and betting when checked to just about always. I'd rather have the 7s in my hand but what can you do.