Why would a guy send me a friend request, then unfriend me the same day?

Just looking for second options. I think he was creeping on my page, but I don't know how an accidental friend request happens.

He's someone I graduated high-school with. He's married with children. So I don't know.

I know he used to like me, but was mad at me cause I had a crush on someone else. I didn't know he was interested. I might have gave him a chance. My life was sheltered anyways so it wouldn't have been the greatest experience.

Why would a guy send me a friend request, then unfriend me the same day?
Post Opinion