The Fox (1968)

Headstrong Ellen (Anne Heywood) and her more demure lesbian lover, Jill (Sandy Dennis), pass their time together on an isolated farm in backwoods Canada. While Jill longs for nothing more than their life together, Ellen is becoming discontented with their relationship. The farm's former owner's grandson, Paul (Keir Dullea), arrives unannounced and asks to spend the rest of his leave from the Merchant Marines living and working on the farm. But Ellen's attraction to him could be disastrous.