Sarah, Bens wife goes to work for fun and to help out a friend. Husband is accused to cheating with neighbor, when he hasn't. Payback is wild and so is the get even afterwards.
Katy volunteers with women who are blind, deaf and retarded. She brightens their lives with a bit of sexual stimulation, the success of which leads in turn to sex between them and men who are similarly disabled. It then expands to include ordinary people who are stunningly unattractive, who would feel too humiliated to be judged by a sighted person of normal intellect. If you will never grow up mentally, maybe sex is just something that feels good -- nothing more and nothing less.