While we have a standard preflop open, we should avoid turning bottom pair into a thin value bet on a board where many straights completed.
We should lean toward betting small on this wet texture to deny equity and leverage our range advantage. Our hand has a backdoor flush draw and an overcard, making it a decent semi-bluff candidate.
Note: Checking is fine, but betting small (20-30% pot) is preferred to put pressure on the SB's wide defending range and protect our equity.
Facing a lead on the turn after we checked back, we have a pure bluff-catcher. Calling is a mix, but we have enough equity against SB's draws and air to continue.
Checking back is the only play here. Our pair of fives has some showdown value, but it is far too weak to bet for value, especially since the 7d completes several straights.
Note: Betting here is a significant error; we don't get called by worse hands often enough, and we risk getting check-raised off our showdown value.