While our second pair is a strong c-bet candidate on the flop, the spade-heavy turn and river require a defensive check-calling posture.
Betting small is the preferred play here to leverage our range advantage and deny equity to CO's various floats and draws.
Note: Checking is acceptable but betting small (33% pot) is higher EV; it forces folds from hands like QJ/JT and extracts value from worse pairs or spade draws.
Checking is mandatory once the third spade and straight possibilities arrive, as our hand has shifted from a value bet to a bluff-catcher.
Checking is the only viable option on the river; we have decent showdown value but cannot expect to be called by worse if we bet.