While talking to the comedian, the Grandfathered star told a bizarre story he had apparently been waiting ages to share!
Speaking of the time when he and wife Caitlin McHugh were trying to get pregnant, Stamos, 55, said he stopped by a fertility clinic to drop off some of his sperm for testing.
"I had to go give a sperm sample," he started. "And I went in this little room… and they said, 'If you need any stimulation or whatever there's videos and there's a TV here.' So I turn the TV on and it's on Fuller House."
The audience roared in laughter.
Stamos added that what went through his mind at that moment was: "If I'm gonna masturbate to myself it's gonna be my old self not the new one."
Phillips, clearly feeling awkward, ended the show with a spout of nervous laughter.
Luckily, Stamos' wild story had a happy ending, as RadarOnline.com readers know, he recently welcomed son Billy with 32-year-old McHugh — and they may be planning for another!
What do you think of John Stamos' odd story? Sound off below.
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