I think you are misunderstand the nature of my comment....it was purely logistical ....living in a large urban city you must have been out ....and got introduced to someone ....spent the night bar hopping ...had a one in stand... because the person lives in the suburbs.....logistical problem . I guy who worked for the same firm I did lived in Manhattan and on the weekends would go stay this his parents in Long Island to visit his girl friend. During the week he was out with work people..other women then on the weekend he'd go see his long time girl friend. It was a logistical problem.
I have absolutely no knowledge of how dating sites work ....so I'm under the assumption that their is a geography type question...and other filters. And it was the arrangement of the filters that's put you two together.
Being single gives you the option of how and when to declare your poly nature.