ships in the night
People, especially those who live together, who do not see very much of each other or are not in the same place at the same time very often. (A shortened version of "ships that pass in the night.") Ever since Georgina started managing the restaurant at night, she and I have been ships in the night. We've had a guy renting our spare room for the last two months. We were worried it would feel crowded, but he works so much that we're like ships in the night with him.