David Burgess tries to spice up his love life by presenting his wife Sara with an erotic video of himself. This excites her so that she videos herself seducing David. Unfortunately, David's colleague Karen gets hold of this cassette (somehow), and passes it on to their boss, Gill. Gill decides he must have Sara for himself, and so pays her a visit. Karen, meanwhile, has a detective photograph the whole thing. She then shows these pictures to David, who soon succumbs to Karen's charms in a fit of pique. After that, things become a little complicated.