Philadelphia bookstore owner Kate comes home from work one day to find her two flatmates in bed together. Joe - a sensitive composer - is mortified. Sean - an irrepressible bad boy - asks her to join in. As they embark on a polysexual menage a trois, Kate wants nothing more than to keep both her admirers happy. However, things become complicated. Kate has told everyone that Sean is gay, but now he and Kate are acting like lovers. Can the three of them live happily ever after - together?