Enticement (2000)

Jill and Paul's sex life is slowly fading, mainly due to Paul's obsessive fantasizing about other women, particularly his stunning neighbor Linda and his luscious colleague Jennifer. Jill tries to spice things up by inviting her sexy bi-sexual friend Andrea to Paul's birthday party. Loosened up by alcohol, Andrea takes things much further than they had all intended. Their sex games certainly improve the party but the end result may be a ruined marriage.