Dark Harbor 1999 on netflix

A bickering couple drive fast through a downpour to catch the last ferry to their island retreat. In a flash, they recognize a crumpled body laying at the side of the road and after much argument they stop, only to find a young man battered and bruised. An offer of summoning the police firmly rejected, the two help the man as best they can although it certainly means missing the ferry… and so starts this thriller: a tale of twisted sexual attraction and ulterior motives.