Despite misgivings at leaving his wife Gail, Tom joins his friend Andy on a holiday in Spain. Andy enthusiastically joins the lager-louts and takes every opportunity available for illicit sex; Tom embarks on a wistful, platonic friendship with Trish. Back home, Andy keeps his infidelity secret and his marriage continues as before; Tom tells Gail of his innocent holiday friendship and the seeds of suspicion are instantly sown ...