They already have an absolutely adorable son Axl together, and Fergie and Josh Duhamel could soon be planning to expand their brood with another absolutely gorgeous baby.

Fergie & Josh Duhamel 'Definitley' Want More Kids?

Duhamel and his Battle Creek co-star Dean Winters talked to Extra's Charissa Thompson about their new show Feb. 27 when Thompson briefly turned the conversation towards the possibility that the superstar couple would give their son a younger sibling.

"So you know I can't let you get away from here without asking about your gorgeous wife," she said to Duhamel. "...You going to have any more kids?"

Fergie Admits To Attending Therapy With Josh Duhamel

"I would love to and she would love to, but right now, it's about figuring out when it's going to happen," Duhamel said. "She's recording and probably going on tour, and the plan is sometime after that, maybe before."

"Maybe I can knock her up tonight," he added

Thompson went along with the joke, making sure Duhamel would give her the exclusive about his efforts to get his wife pregnant.

"That'd be great. Let us know how that goes," she said. "Please come back for the follow-up."

Duhamel then took the joke one step further, promising her he'd give her an update as soon as he had one.

"I'll direct tweet you," he replied. "'Things went well. I'll let you know in a few weeks.'"

Duhamel and Fergie married in 2009. Their son was born in August, 2013.

Tags: Fergie Josh Duhamel