In this universe, everyone has a fated mate. You can tell this by the mark you have on your inner wrist, a small something etched into your skin that will help you find them later in life. Bucky and Steve are one couple that are lucky enough to have two fated mate marks. One for eachother and the other for someone they have yet to meet. What happens when they smell a sweet omega in the park, that just so happens to have two mark on her wrist? Their marks?