Kevin (Jason Lee) is the neighbor of Chris (Will Arnett) and Reagan Brinkley (Christina Applegate), who meets Ava (Maya Rudolph) while she is sitting with their baby. Although originally jealous of the Brinkley's regard for him and therefore sarcastic on their first meeting, she needs help when she finds that the safety belt on the baby's high chair won't unlock. Forced to call on Kevin to rescue the child, Ava is very grateful for his assistance and a budding romance begins. Now if she can just win over his daughter, Mckenna (Chloe Csengery) who lives with him!