[JooWish622]

The least volatile line you can take here OOP is to bet 50 on the flop and then again on the turn if he raises you. If he raises your flop bet to 100, bet 100 on hte turn and fold to a raise would likely be the best line to take. Not many players would raise your bet there with one pair and it saves you a river bet if you just check/called the turn and now had to call a river bet.

This stop and go should signify real strength, defines your hand clearly, and you may even get a river check from A9 after doing so, not likely but possible.

If the 9 pairs on the turn, I would bet turn and 1/2 pot river