turned weak two pairs

This person has been actively hitting the bet and raise buttons on his screen. He didnt like to fold to 3bets all that much, thats why I decided to just flat pre. Folding couldnt be bad either, but I wanted to play as many pots as possible with him in position. So far he has been cbetting almost 100% of flops, so I don´t wanna fold the flop (or do I?)? Do I fold to his turn c/r? fwiw, he tank-checked and then quickly raised.

$0.5/$1 No Limit Holdem
3 players
Converted at weaktight.com

Stacks:
BTN ($200.60)
SB ($100.00)
Hero (BB) ($103.50)

Pre-flop: ($1.50, 3 players) Hero is BB :6h: :4h:
BTN folds, SB raises to $3.50, Hero calls $2.50

Flop: :8s: :3d: :4s: ($7, 2 players)
SB bets $7, Hero calls $7

Turn: :6s: ($21, 2 players)
SB checks, Hero bets $12, SB raises to $31

preflop is fine. I'm not folding flop, especially with a habitual c-better like him. not folding turn either against this small c/r when you're read is he's raising a lot (perfect card to represent when you As8 for example or absolutely nothing) we dont have the odds to try and boat up, but we are still ahead against a part of his range and have (ok not many) outs against the other part.

If you called I think river is more interesting to see if we think we can valuebet there or when he shoves a blank/spade...

I also call Pre/Flop.
I think here we have to call as we have position.
Vs this villain, I would also call any bet on the river if no 2/5/7/8/spade appears. Otherwise, it will depend on the bet size.