Chelsea is jealous when Charlie's ex fiancé, Mia, calls him--perhaps rightfully so. Meanwhile, Judith goes into labor, Herb is incapacitated, and Alan runs into his ex-girlfriend and receptionist at the hospital.
Chelsea encourages Charlie to help his ex-fiancé Mia launch her music career, but does he still have feelings for her? And what if she's a terrible singer? Meanwhile, Alan wants Charlie to let Melissa move in with him.