Mark Harmon wasn’t initially thrilled with his acting debut.

The actor, 73, recently joined Kelly Ripa and Mark Consuelos Live with Kelly and Mark in Palm Springs on Wednesday, November 13. During their conversation, he told the daytime talk show hosts that his first role was actually alongside his father, football and broadcasting icon Tom Harmon.

The NCIS star explained that his father was the spokesperson for Kellogg’s and he was asked to join him in a commercial for one of its products, specifically Product 19 cereal.

“I was in a commercial in the backyard eating cereal, which never happened,” he joked with Ripa, 54, and Consuelos, 53. Harmon confirmed that he had just entered high school at the time.

“So I imagine my own children. Would that be embarrassing for you…” Ripa began before the Emmy nominee immediately interjected and confirmed it was “humiliating.”

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Although people didn’t start to recognize him, the commercial “changed its) direction a little bit,” Harmon said. “I think I saw something, that crew, those people around, that I understood.”

Consuelos intervened and said, “The salary is nice too. Did you pay for that commercial?”

“My father did that. I think so,” Harmon said with a laugh. “I think they have laws against that now,” Consuelos added, and Harmon replied, “Not then!”

Since that first commercial, Harmon has starred in several projects Crazy Friday Unpleasant Moonlight And St. Elsewherebut he stuck to his NCIS character, Special Agent Leroy Jethro Gibbs, for almost twenty years.

Harmon starred in the military police procedural for 19 seasons until his departure in 2021. Since its premiere in 2003, the series has spawned five spinoffs: NCIS: Los Angeles, NCIS: Hawai’i, NCIS: New Orleans, NCIS: Sydney And NCIS: Origins.

Speaking to PEOPLE in 2019, Harmon revealed the secret to his success, which he attributed to his late father’s advice.

“My father taught me: if it’s not true, don’t worry about it,” said the NCIS star said of his father, who died in 1990 at the age of 70. ‘I come from a working-class background and I’m proud of that. You have to get up every day and just do your best”

Harmon explained at the time that even though his father had died nearly thirty years earlier, he continued to carry out his father’s advice.

“Work your best, and don’t let the effort show,” he said. “Also: treat people the same, not based on who they are or what they are. Show them general kindness. Don’t be colored by their fame or profession. I don’t get that excited when people blow smoke up my ass. You have to stay honest.”

Harmon serves as narrator and executive producer NCIS: Originsairs on CBS Mondays at 10pm ET.