I Married A Monster From Outer Space

Actors Tom Tryon and Gloria Talbott play the films lead characters.
Plot summary
A young couple marries, but almost from the start the bride notices her husband is acting strangely. One night she follows Bill when he goes for a walk and finds that he's not the man she knew but an alien meeting up with his like.He eventually explains to her that all the females from his planet were killed and that the aliens from another world are taking over earth male bodies so that they can mate with women.