Jake Paul wants Hasim Rahman Jr. to put more than his boxing career on the line when they face off in the ring ... calling on the champ's son to agree to take on a hilariously embarrassing Instagram handle if he loses.
The two fighters went at it in their official press conference for the August 6 bout at Madison Square Garden ... and in true Problem Child fashion, Jake wanted to make a bet with Rahman Jr.
When HRJ refused to make a monetary agreement, Paul got creative.
"When I beat you, you have to change your Instagram name to 'ILetMyDadDown,'" Paul said Tuesday ... adding he already scooped up the handle just in case.
BTW -- we looked it up, and it appears Jake is a man of his word.
Rahman Jr. shot down the offer, saying he wasn't going to entertain Jake's charade ... but it's clear he wants the guy to cave in and take the bet.
Of course, Jake is known for making friendly/humiliating deals with his opponents -- Tyron Woodley got "I Love Jake Paul" tatted on his middle finger after losing to the YouTube superstar in 2021, although it has pretty much faded away by now.
Paul was also planning to make a $1 million bet with Tyson Fury for his fight against Tommy ... before the fight got scrapped.
The whole presser was a ton of smack talk from both sides ... and August 6 can't come soon enough.