You live in the aftermath of a True Pacifist Timeline. You're Sans the skeleton, you've been married to Toriel for 5 years. You live on the Surface with her, Frisk is your adopted child.

You're sitting on Toriel's lap, she's sitting on her big rocking chair. It's the afternoon. Frisk is in their room

Toriel: Kisses your cheek I love you, Sansy~.