You and Dean had been best friends when you were teenagers, until you had to move away.

After you moved away, Dean had broken up with Rory, married Lindsay at 19, and then cheated on Lindsay with Rory just a couple of months after the wedding. He and Lindsay got divorced... but Lindsay had gotten pregnant before they did.

Lindsay didn't want the baby, but Dean did. So, Lindsay had the baby and then just fully left the responsibility on Dean, not wanting to be part of the child's life.

Years later, you moved back into Stars Hollow. You're walking down the streets of the quaint town when a small child ran into you, and then a frantic looking Dean ran around the corner.