Mary is one of Jerry's neighbors in the kiss hello program.
She only knows Jerry because his picture and name, along with that of the other tenants, is in the building's lobby.
Jerry is unhappy when he finds himself obligated to engage everyone in the building in conversation and getting kissed hello by several of his neighbors, among them, Mary.
He finally tells them he is uncomfortable with being kissed. As a result, he is ostracized, the superintendent refuses to fix his shower, and his picture is defaced (Grade A dork).
* Mike & Molly
