Comedian Will Ferrell, who announced in July he is expecting his second child with wife Viveca Paulson, has revealed the new baby is a boy. Ferrell appeared on The Late Show with David Letterman on Monday night and the talk show host asked him if he knew the sex of the upcoming arrival. The 39-year-old joked, "You know, I don't know if we do. I've gotta check my Blackberry." He then explained, "Well, we do know, but I forget if we're telling people. I told the Today show we weren't telling them. But it's a boy!" Ferrell and Paulson, 37, an art auctioneer, have one son, Magnus, two. When Letterman asked what Magnus' reaction was to having a new brother in December Ferrell added jokingly, "He doesn't like it. He's in denial about it... I'm like, 'You better live it up now, 'cause number two is coming and it's not going to be fun for you!'"