What's Channing Tatum most terrified about when it comes to his impending fatherhood?
"I mean, I don't think there's one thing that doesn't terrify you, but in the most unbelievably beautiful way," the 32-year-old Magic Mike star gushed. "Someone said it's really like watching your heart jump out of your body and run around, and I think that can possibly be the coolest thing that I've heard of."
As for how his pregnant wife is adjusting to her growing baby bump, Tatum said, "I mean, women just sort of turn into like animals in this sort of stage that they're in."
"Are you calling her an animal?" Mara asked.
"She's a complete animal right now!" he joked. "You can ask her, but in the most beautiful like humanistic animal-y way. You know she works out all of the time, eats right, impeccably right. She's just a machine."
Meanwhile, Tatum's Side Effects costar and father of four Jude Law has some parenting advice for the Sexiest Man Alive.
"I just warned him," Law cracked, adding, "I just said, ‘Make the most of it while you can, brother.' They will break you. Sleep while you can."
For the full interviews with Tatum, Mara and Law, don't forget to watch E! News tonight at 7 and 11:30 p.m.!