Fish limps CO. SB completes I have AQT65 on the BB. SB draws one, I draw 3 and fish draws 3.

I get 86532 and SB leads. I raise, fish calls, SB calls. SB discards one I pat and he leads, I call fish folds. 3rd street goes pat pat. He donks again. He can value bet 86542, 86543 with some frequency I guess but I have never played this guy. Should I fold 86 with some frequency ?

Thank you guys.