Gross spot but I think because villain can have more Kx we should fold. K9,KJ,K6s get played by BB so much more KKKxx boats. We bet polar as well can't see worse value hands that shove on it. Bluffs ? Well that's hard to have those, I have no idea what BB should bluff here and think the population doessnt either / not willing to do it imo

Looking over pot odds, looks like a fold. Don't know what people can bluff apart from J9 or A9. Maybe vs super good player or not aware player we can more safely call.
But I don't hate calling, I hate to realize if this is never bluff ( which is fair assumption) i would be doing huge mistake by calling

Yeah I thought folding was obviously the right play but I wasn't disciplined enough to lay it down. :(

Even if some people are capable of bluffing here, I probably block most of the hands they do it with.

I think folding is fine, i can see only one hand which you can beat this is kt, because you cant have ak kq and maybe he can shove kt, but its only assumption, so my personal opinion that folding is right play.

Easy fold.
first, it is a multiway pot. If villain is competent, he should only call a K or better on the turn. Does he really turn bad K into a bluff after that action?
Second, if villain is bluffing, it has to work 60% of the time. Does villain really think that his bluff works that often against your action. Even if you fold 99 here and call everything better, you are probably folding too less. (Depends on how you play KQ, do you play a different sizing on the riv?)

this hand is a punt. it kind of looks like a cooler but in reality this is just a massive river mistake from you. the pot was 4 ways, you bet the flop 4 ways and then tripled off on a paired board vs the bb who mostly always has Kx himself. so your range is EXTREMELY strong and probably contains no bluffs (bluffing here would be suicidal imo given the fact that the bb always has a K and can also have some boats.)

on the river it is actually pretty marginal whether to bet or not, if you think that bb is a bit more of a station and he can call you with a hand such as QT or Kx then of course you have to bet, but if he folds these hands then you need to be checking back because BB has every single KJ/K9 combination, as well as some K6s.

so I think I like going for the block sizing, around 25-30% of the pot, so that we could value bet a hand like QT ourselves, and we get value from all of villains QT as well as Kx and don't narrow his range to the extent that he just has a boat and we get jammed on. pot is far too much, and is going to force OOP to fold all of his QT as well as his Kx worse than lets say KT, but even that may fold. so you are just getting him to fold all of his hands weaker than 99 and continue all hands better. so if you can only pot or check then checking is clearly much higher EV and you should always be choosing that option.

however, I think that blocking is higher EV than checking, so I would go with that and vs a raise I would still probably fold but consider it a bit more because of our small sizing. however again I would probably still bet fold because unless he is turning QT/Kx in to a bluff then our call will be massively losing, as we don't beat any value combo's.

ps love the term 'baby full house' haha :P