Claiming electronic cigarettes "don't work," the music mogul eagerly pulled out a pack of cigarettes to light up after taping an episode of his Fox singing competition on Thursday.
"There are a lot of boring things that happen when you have a baby," Cowell, 54, told reporters with a cheeky smile. "[You have to get rid of] sharp edges, cigarettes, alcohol … then there's [baby-proofing] the toilet. But I'll have a smoking room!"
News broke in July that Cowell was going to be a father with his girlfriend Lauren Silverman, who was still married. At first, the parents-to-be kept their distance from each other, but now they could not look more like a happy couple.
"She is really interested [in The X Factor]. We work on some ideas together and it is good," says Cowell, who has shared kisses and exchanged opinions with Silverman in the audience during tapings of the show. "She really gets into the song choices. She came up for a very good idea for [one of my acts,] Alex & Sierra, which I think they might do next week."
With X Factor ending on Dec. 19 and the baby due in early 2014, Cowell is looking forward to a relaxing three-week vacation in the Caribbean before heading back to work on Britain's Got Talent.
And while he's enjoying the calm before the storm of parenting, that doesn't mean he's not excited to welcome a son with Silverman in the new year.
"I was just texting with [One Direction's] Louis Tomlinson last night because his mom is pregnant and is going to have the baby the same time as Lauren," he said, beaming. "So it's like, who is going to go first? I think I am going to win."