A event that occurs when you are walking towards someone and you both try to get out of each other's way but end up choosing the same path.
Walking down the street, hallway, or just walking in general and you see someone coming at you and at the last second you both turn to get out of each other's way, but just get in each other's way again. And then you try to go the other way, and they go that way too. Basically it just keeps going until you either finally guess right or, in the more extreme cases, you decide to just stop and tell the person where you are going.
"We same-stepped for a while before I just decided to stop and ask him which side he wanted to pass me on so I could go the opposite."
"John tried to go to the right, and avoid Jill, but he ended up same-stepping with her. It was an awkward dance."