Sean Duffy would like you to watch his family making pancakes.

They have cooked breakfast together twice on national television, once just last month — man, wife, and children, gathered around a stovetop as a Fox News host prompts them to describe this most wholesome of Saturday morning pastimes.

“For us, it’s not just eating the pancakes. It’s actually making the pancakes,” Mr. Duffy said in a 2017 segment, bouncing a baby on his hip as the rest of his kids smiled uncomfortably at the camera. “It becomes somewhat of a family affair.”

The Duffys, who had eight children at the time and would go on to have a ninth, were proud to highlight their unusually large family. Mr. Duffy’s wife rattled off the kids’ names before mixing the batter, noting that two were away at Catholic camp, praying the rosary. When it came time to fire up the burner, she stepped aside. In this all-American household, the roles were clear: Mom whisks and Dad mans the griddle.

As the camera panned out to Sister Sledge’s “We Are Family,” Mr. Duffy wrapped up another segment in what has essentially been an ongoing reality TV show showcasing much of his adult life.

Over three decades, Americans have watched him evolve from a sex-hungry 25-year-old on MTV’s “The Real World,” gyrating with a woman on a pool table, to Secretary Duffy, a devoutly Catholic husband and father at the helm of President Trump’s Transportation Department, pushing young Americans to have families as large as his own. Mr. Duffy and his wife, the Fox News host Rachel Campos-Duffy, like to call themselves “the longest-lasting (and most fertile) couple in the history of reality TV,” a title they trace to a mid-2000s issue of TV Guide.