E! News has unearthed footage from more than two decades ago, when the father-son team sat down together in advance of the 1990 release of Rocky V, and even then their playful bond was evident.
When asked how it was playing father-son in the film as opposed to real-life, their good-natured ribbing began in earnest.
"Uh, how 'bout for you? Time's up," Sly quickly asked and answered several times before finally relenting and allowing his son to answer the question.
"The movie character was much more difference than, you know, life is for real."
"Are you saying Rocky's nicer?" Sly joked, prompting the E! News interviewer to ask the then-13-year-old actor if he'd rather have Rocky for a dad or his own movie star papa.
"This I wanna hear," the elder Stallone replied.
"Him!" Sage laughed.
And like any proud father, Sly—who reunited with his son onscreen six years later in Daylight—wasted no time in gushing over his offspring.
"Now he can look in the mirror and say, you know, I did it. I'm not just a hanger-on, I'm not just a kid who's there who has no ability. I acted with my father and in some scenes I blew him away! Not bad."
He will be laid to rest this weekend.