The Saturday Night Live star and father of six speaks with the talk show host about welcoming five children in seven years with Hilaria.
"I tell people my wife is a collector. Some people collect cars, some people collect watches, artwork. My wife collects babies. She likes babies," he quips. "When the baby gets to be 3 years old, when they're not the vending machine of joy they used to be, we look at each other and say, 'Time to have another!'"
Though the couple shares one girl and four boys, the 62-year-old actor has no intentions of trying for another girl.
"I'm not going to keep trying, no, I'm done trying. It's either going to be fine or my wife's going to get remarried, one or the other," he jokes. "She's going to marry a guy who produces girls."
When DeGeneres brings up a photo of Alec getting a pizza while his wife was in labor earlier this month, he denies the claims and brings Hilaria and their baby boy into the camera frame.
"That's not true, Ellen, and I resent my wife implying that I put my gastronomic needs ahead of her obstetric needs," he insists.
"In his defense it was my idea," Hilaria admits, saying for previous births she hasn't allowed her husband into the delivery room until after she's received an epidural because "he drives [her] crazy."
But due to COVID-19 restrictions, Alec had to stay in the room the entire time for the birth of Eduardo.
"I'm like, you need to eat something because later on I'm going to kill you," Hilaria jokes.
She also tilts baby Eduardo to the camera so the audience can see the precious tot.
"He's not a girl, but he's perfect," the proud mom says, showing off her 9-day-old son. "We have it down by now."
Alec also opens up about being an older father to young children, sharing, "On one level you appreciate it more. When I was younger and work was primary, I had to divide my time with that."
In addition to his five children with Hilaria, Alec also shares 24-year-old daughter Ireland with his ex, Kim Basinger. In a funny version of his game show Match Game, Alec is asked to identify whether an image is of one of his children or another baby. He manages to get almost all of the answers wrong, including identifying baby Eduardo.
"That's your baby that you just had nine days ago!" DeGeneres says laughing. "It has not changed that much."