That only shows how stupid the villain is, to believe that if they beg they can be spared.
I also believe BB only begged WB to deceive him. Since BB really respected WB once in a time, and because he knew WB has a very soft spot for his sons, considering that WB even hugged Squardo after stabbing him. But WB didn't fall for BB's trick again after being deceived for 20 years, and he tried to kill him by quaking his ass, though BB proved to be too tough to be killed even by WB. When BB got poisoned by Magellan, he didn't beg for antidote. BB even later says to Shiryu that being afraid of death is something that the only losers would do.
I don't think it's necessary for Kaido to be dumb, so I hope it won't happen.
I also believe BB only begged WB to deceive him. Since BB really respected WB once in a time, and because he knew WB has a very soft spot for his sons, considering that WB even hugged Squardo after stabbing him. But WB didn't fall for BB's trick again after being deceived for 20 years, and he tried to kill him by quaking his ass, though BB proved to be too tough to be killed even by WB. When BB got poisoned by Magellan, he didn't beg for antidote. BB even later says to Shiryu that being afraid of death is something that the only losers would do.
I don't think it's necessary for Kaido to be dumb, so I hope it won't happen.