Eric Stonestreet, Jesse Tyler Ferguson

Modern Family's family is about to get bigger. At the end of Season 2, Cam (Eric Stonestreet) and Mitchell (Jesse Tyler Ferguson) decided they wanted to adopt another child. And if you thought that was just a sentimental aside, you think wrong!

Executive producers Christopher Lloyd and Steve Levitan say the third season of ABC's Emmy-winning comedy will explore the lengths the couple will go to get another child. "If last season was about [the families] growing up, this season is about them growing," Lloyd tells TVGuide.com, revealing that Cam and Mitchell want a baby boy since they already have a girl in Lily.

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"We're doing quite a few stories on that topic," Lloyd says. "We're trying to treat it in a real way. You don't just decide you want to adopt a baby boy and then rub your hands and it happens. You have to sign up with agencies. The agencies have to come and interview you and take a look at the environment the child would be raised in. Often, you have to more or less audition for the birth mother and see how she feels about placing her child with you. We are sort of exploring all of these steps along the way to them actually having a child."

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One of the first hurdles comes in the premiere episode. Mitchell, who's been working nearly non-stop since they adopted Lily, realizes he may not be entirely fit to raise two children.  "Mitchell, who hasn't shouldered so much of the raising of Lily, starts to have some fears about how he will be as a father to a boy, in particular," Lloyd says. "Because he has a little bit of a troubled relationship with his own dad and in our season premiere when they go to a dude ranch, he's trying to really assess how much of a man's man he is and how prepared he is to have a boy in the house."

At the same time, Cameron, who's been the stay-at-home mom (See: "Mother's Day" episode), begins to realize he's too close to Lily. "He is with her all the time and he's really like a virtuoso in terms of the things he can do while actually holding her," Lloyd says. "There's almost no household activity he can't do without having her on his hip. But he starts to fear that Lily has become so close to him that she's not going to tolerate a new child in the house so he's trying to sort of break himself of the Lily habit in one episode."

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Both Stonestreet and Ferguson agree it was time to show the adoption process since the comedy began with them just getting custody of Lily. "I think a lot of people, gay and straight, have to look to alternate means to expand their family," Ferguson says. "There's a lot to be told in that story. We met them at the peak of their joy, so it's going to be really nice to see their struggle." Adds Stonestreet: "It's a story that needs to be told because so many families go through that process so we're excited to do it in a comedic way."

The adoption may not go as planned, though. "You're going to see them go through a lot of ups and downs this season with a surprise ending that we don't want to reveal yet," teases Levitan.

Modern Family premieres Wednesday at 9/8c on ABC.