During the second half of the Season 3 premiere hour of Modern Family, Mitch and Cam invite the entire family over to celebrate the good news: They're adopting another baby! Unfortunately, the fun quickly turns to disappointment when they realize Lily may not respond well to a new addition. Meanwhile, Claire and Jay go head-to-head as they attempt to prove a point. Sounds like a regular drama-filled Pritchett-Dunphy get-together! Modern Family Season 3 premieres on Sept. 21 at 9 p.m. ET on ABC.