A clip from the episode was released earlier in the day showing them discussing same-sex marriage and support for transgender youth. It marks Biden's first appearance on the Comedy Central show since he took office.
Guest host Penn — who rose to fame in the Harold & Kumar films and was later a White House staff member in the Obama era — asked Biden about his evolution on marriage equality. The Designated Survivor also noted that he and his partner, Josh, have been engaged for the past five years.
Biden, 80, shared his "epiphany," saying he was a senior in high school when, while with his father, he saw two men kiss for the same time. He said he looked at his dad, who told him, "Joey, it's simple — they love each other."
He continued, "It's just that simple. It doesn't matter whether it's same-sex or a heterosexual couple. You should be able to be married. What is the problem?"
Biden told Penn, who said his aunties and uncles were disappointed he hadn't married his partner yet, to listen to his relatives and "get married. Do it now. Don't wait."
As for trans kids dealing with regressive state laws, Biden said it's a "harder thing." He said what is going on in Florida is what his mother would have called "close to sinful."
"It's terrible what they're doing," he continued. "It’s not like a kid wakes up one morning and says, ‘You know, I decided I want to become a man' or 'I want to become a woman' or 'I want to change.' What are they thinking about here? They are human beings. They love. They have feelings. They have inclinations that are... It just, to me, is, I don’t know is, it's cruel."
Biden said the way to fight it is to "make sure we pass legislation like we passed with same-sex marriage. You mess with that, you’re breaking the law and you’re going to be held accountable."
Penn, 45, first revealed he was in a same-sex relationship in 2021. He wrote about his relationship with Josh (whose last name has not been revealed) and their engagement in his memoir You Can't Be Serious, saying that they, at that point, had been together for 11 years. He said that while he always maintained an open attitude, members of his and his fiancé's families are"quiet" about their personal lives and he was respectful of that.
"I've always been very public with everybody I've personally interacted with. Whether it's somebody that I meet at a bar, if Josh and I are out or we're talking to friends," Penn told People at the time. "But Josh, my partner, my parents and my brother — four people who I'm closest to in the family — are fairly quiet. They don't love attention and shy away from the limelight."
Whenever the Getting Warmer with Kal Penn host does get married, Cardi B has offered to officiate.
Penn's schedule may be getting even busier — potentially. He's expressed interest in becoming the full-time Daily Show host after the departure of Trevor Noah in December — and this interview with the president can only help his chances.
"I don't know if I'm supposed to be coy or not, but hell yeah," he said on the Today show last month when asked if he'd take the full-time gig. "I appreciated working in the White House so much. It was an honor. [Plus] My background's in comedy."
On Monday, Penn told The Wrap he was "very honored" to have Biden "as my first guest for my first night of hosting The Daily Show. He was incredibly gracious."
Others who have temporarily filled the seat include Chelsea Handler, Sarah Silverman, Hasan Minhaj and Leslie Jones. Al Franken and John Leguizamo will both sub later this month.