Summary: Sammy is describing how he sees his middle and oldest siblings (ONE-SHOT)
Sam's second 'parents'
Lily was like Sam's mother she took turns with dean to calm him down when he was upset or had a nightmare when he was growing up. She made sure he remembered his manners; she cut off the crusts of his sandwiches, Lily was like Sam's mum.
"Sammy it's ok, we've got you, nothing's going to hurt you. We'll always be here for you"
"Do you want the crusts off your sandwich Sammy?"
"What do you say before I give your sandwich Sammy?"
"What do you say after you burp Sammy?"
But they still had their youth so they still argued like siblings, still made decisions like children sometimes,
"Sammy that's not fair you got to watch your show first yesterday it's my turn today"
"Sammy come on, you can do your homework later let's do something fun today"
Dean was like Sam's father he took turns with Lily to calm him down when he was upset or had a nightmare; he protected him and Lily when their real father was out hunting, he would make sure they always had some kind of dinner on the table,
"Sammy nothings gonna get you we won't let it"
"Sammy, Lily, stay here and I'll take care of it"
"Sammy, want some grub? Its mac 'n' cheese just the way you like it"
But they were still brothers so they still fought like brothers, and dean was a kid so he still did stupid stuff like a kid.
"Sam! I swear to god if you don't give me my pie I'll kick your ass!"
"Sammy! Have you seen the food money?"
"Hey, Sammy! That looks fun"
So, yeah, Lily and dean were his older brother and sister and yes, technically John was their father and their mother was in heaven but Lily and dean will always be mum and dad to Sam.