He likely thought you had a better q than him and took the 9 pairing as a chance to Bluff you off it.

The problem is we block draws with our hand. And he could also be bluffing with the best hand. Just call with a Q, it's easier. Our range just bet bet into 3 people. We have more than enough Qx+ to ever consider making a hero call like this.

In my opinion this call is too ambicious, i mean what are you trying to beat? yeah he checked called checked called but that doesnt mean you are gonna pay him off just because it doesnt make any sense. right?

bet flop check turn
if he check this river maybe you can bluff he.
bet turn you have about +-0EV
check turn maybe you have more i think

I put everything that makes sense for him to have in equilab and even if he leads his whole range (including all Ace high and better) I need 33% equity to call OTR and have 30.5-31.5.
And that's a lot of offsuit 9x...

CO 31.53% 21.62% 9.91% KsJc
BB 68.47% 58.56% 9.91% 9h9s, 4d4h, KJs-KTs, JTs, J8s, T8s, AcQc, KcQc, AcJc, QcJc, AcTc, QcTc, Ah9h, As9s, Kh9h, Ks9s, Qs9s, Jc9c, Tc9c, Ac8c, Kc8c, Qc8c, 9c8c, Ac7c, 9c7c, 8c7c, Ac6c, 8c6c, 7c6c, Ac5c, 7c5c, 6c5c, Ac4c, 5c4c, Ac3c, Ac2c, AQo, KTo+, QTo+, JTo, Ad9h, Ad9s, Ah9s, As9h, Ac9h, Ac9s, Kd9h, Kd9s, Kh9s, Ks9h, Kc9h, Kc9s, Qd9h, Qd9s, Qs9h, Qc9h, Qc9s (card removal doesn't show up here but it's on)

If he only leads AQ and better + J high and worse this is the result:
CO 30.61% 30.61% 0.00% KsJc
BB 69.39% 69.39% 0.00% 9h9s, 4d4h, AQs, JTs, J8s, T8s, AcJc, QcJc, Ah9h, As9s, Kh9h, Ks9s, Qs9s, Jc9c, Tc9c, 9c8c, 9c7c, 8c7c, 8c6c, 7c6c, 7c5c, 6c5c, Ac4c, 5c4c, AQo, Ad9h, Ad9s, Ah9s, As9h, Ac9h, Ac9s, Kd9h, Kd9s, Kh9s, Ks9h, Kc9h, Kc9s, Qd9h, Qd9s, Qs9h, Qc9h, Qc9s

It's pretty close to 0EV so probably better to just fold. Anyway I have another note on him now :D