It's bad to cheat with someone who's married.
Joey is a single man who lives alone and his neighbors wife has shown quite an interest in him.
Joey wants to find a sexual partner.
Joey does not reciprocate with the wife but rather makes a profile on a dating website.
Joey ends up becoming physically involved with his neighbor's wife.
Joey meets someone who wants to hook up with him online.
Joey's neighbor finds out, and he blames his marriage failing on him.