The fifth in the Turn Of Fate short television movies, Danger By Night (bottom left image) is from 1957.
Alan Kevin (David Niven) and his wife, Elizabeth (Katharine Bard), are working in Haiti.
While people think they’re the perfect couple, they are planning to divorce when they return home to USA.
However, a prowler at their home causes Alan to move back in his wife’s bedroom.
When he returns, Alan kills him and he declares that he had to do that to get back with his wife.
I was waiting for the twist but that was it.
Movie pages here.