QQ utg

praying to god he has tens or jacks basically. though i only play 6max.

When are we planning to stop betting?

We don't know your opponent, but let's assume he is an "average player".

Those players are usually limping and calling with crap like AT+ 22+ and connectors.

Flop gives us 3 small cards, that's good, he probably missed sets and draws. No high cards too, so we are not afraid of Ax hands.
But he calls our bet.
Why? Did he hit his set? Maybe he is just stubborn with overcards or draw?
Turn completes straight draws nicely
Then we bet again and he calls again.
Why? Of all his hands he should fold all Ax, underpairs and missed hands, yet he calls. 33 - 77 beats us. Its unlikely for average player to call without at least overpair hand here. Most of those hands beats our QQ, so that call indicates we are no good most of the time.
River gives another low card - 8.

Ok, what he CAN call with. He will obviously fold all his missed draws, underpairs and one pair hands. What is left is pairs 33 - AA, straights and some 2 pair hands (he would bet them earlier probably). Most of those hands beats our QQ and small bet will not get enough folds.

Then why do we bet river? This one bet can save you 22bb, and that is the only part i would play differently. I would x/c if i had a read that he can bluff river and x/f otherwise.

Short stack player calling UTG's open raise at nl2.. I would assume that we are ahead until we face a raise. So I would play this hand similarly.

River bet is really bad. Even on turn I would probably just x/c and give up R. Turn card is really scare not only for us.[*]

If we keep betting, villain keeps calling and the board keeps growing drawy. We should stop the aggression.
Plus our hand is not a monster.