Luc Béraud - Plein sud AKA Heat of Desire (1981)

Quote:
In France in the near future, revolt and chaos erupt. A right-wing politician, Philippe Muphand, is set to take control when his lady friend Caroline walks out, announcing she will take up with the first fool she sees. The fool is Serge Laine, a professor and author of the prize-winning “Le voyage qui ne finit pas,” headed to the train station for tickets to Barcelona where he and his wife will enjoy a second honeymoon and he will lecture at the university. Caroline seduces Serge, and he soon abandons wife, family, job, and honesty to embrace Caroline, the romanticism of Jack London, and murder.