Little Brother

Dean's usual nickname for Sam is Sammy but he sometimes also calls him "little brother" and its variations. Dean calls Sam "little brother" a total of 9 times, including 4 times in Season 8.

Episodes

1.06 Skin

The Shapeshifter, posing a Dean, compliments Sam's fighting skills.

Shapeshifter!Dean: Not bad, little brother.

1.18 Something Wicked

Sam and Dean try to convince Michael to play bait for the Shtriga.

Michael: You said you were a big brother.
Dean: Yeah.
Michael: You'd take care of your little brother? You'd do anything for him?
Dean: Yeah I would.

After their fight with the Shtriga, Dean asks Sam if he's okay.

Dean: You ok little brother?

2.14 Born Under a Bad Sign

Meg, possessing Sam, tells Dean he can't hurt her withourt hurting Sam.

Meg!Sam: How? You can't hurt me. Not without hurting your little brother.

2.21 All Hell Breaks Loose: Part One

Dean tells Sam he'll take care of him after Jake Talley stabs him in the back.

Dean: I’m gonna take care of you. I’m gonna take care of you. I’ve got you. That’s my job, right? Watch out for my pain-in-the-ass little brother?

2.22 All Hell Breaks Loose: Part Two

Dean summons a crossroads demon to make a deal and bring Sam back for the dead.

Crossroads Demon: Following in Daddy's footsteps. You wanna make a deal. Little Sammy back from the dead, and—let me guess— you're offering up your own soul?

3.05 Bedtime Stories

Sam summons a crossroads demon to try to learn how to get Dean out of his deal.

Crossroads Demon: Aren't you tired of cleaning up Dean's messes? Of dealing with that broken psyche of his? Aren't you tired of being bossed around like a snot-nosed little brother? You're stronger than Dean. You're better than him.

3.07 Fresh Blood

Dean teaches Sam how to take care of the Impala.

Dean: That's my job, right? Show my little brother the ropes?

3.10 Dream a Little Dream of Me

When Jeremy Frost turns Dean's dream into a nightmare and has to face a version of himself who tells him about his insecurities.

Dream!Dean: No, all there is is, "Watch out for Sammy. Look out for your little brother, boy!" You can still hear your Dad's voice in your head, can't you? Clear as a bell.

3.12 Jus in Bello

Victor Henriksen tells Nancy Fitzgerald that Sam and Dean are dangerous criminals.

Henriksen: The most dangerous criminals you’ve ever laid your eyeballs on. Think Hannibal Lecter and his half-wit little brother. Do you know what these guys do for kicks? Dig up graves and mutilate corpses. They’re not just killers, Sheriff. They’re Satan-worshipping, nutbag killers.

4.14 Sex and Violence

Nick Munroe poisons Dean and tells him that he can be his little brother.

Munroe: You really should have wiped the lip of that thing before you drank from it, Dean. I should be your little brother. Sam. You can't trust him. Not like you can trust me. In fact, I really feel like you should get him outtta the way, so we can be brothers. Forever.

5.05 Fallen Idols

Sam tells Dean he wants to be treated equally.

Sam: Dean, one of the reasons I went off with Ruby... Was to get away from you. [...] It made me feel strong. Like I wasn't your kid brother.

5.07 The Curious Case of Dean Winchester

Patrick tells Sam that he doesn't have to stay sat at "the kiddie table".

Patrick: You're not the little brother anymore, Sam.

5.10 Abandon All Hope...

Lucifer tells Sam that he's a little brother like him.

Lucifer: I was a son. A brother, like you, a younger brother, and I had an older brother who I loved. Idolized, in fact.

5.13 The Song Remains the Same

Michael refuses to heal Sam until he talks to Dean.

Dean: Fix him.
Michael: First, we talk. Then I fix your darling little Sammy.

6.08 All Dogs Go to Heaven

Crowley blackmails Sam and Dean into working for him.

Crowley: Come on, Dean, smile. It's not that bad. Here's incentive – you bag me a live alpha, and I'll give you little Sammy's soul back, with a cherry on top.

6.11 Appointment in Samarra

Soulless!Sam tells Bobby Singer that Dean only cares about the real Sam.

Soulless!Sam: Dean doesn't care about me. He -- he just cares about his little brother, Sammy, burning in hell. He'll kill me to get that other guy back.

7.08 Season Seven, Time for a Wedding!

Dean talks about Sam and his issues with a waitress at a strip club.

Dean: Well, things are looking up now that your shift's over. All right. Uh, here's the deal. I have this friend. He's got this younger brother. Right? Cannon's a little loose. You know, his reactor blew a while back. It's not good. Um... My friend – he's, uh... He's kind of been sitting, waiting to see if he goes guano again.

The waitress tells Dean that Sam still needs him.

Waitress: See? Baby bro needs you after all.

8.09 Citizen Fang

Benny Lafitte tells Dean he's not afraid of Sam but Dean tells him he should be.

Benny: No offense, Dean, but your little brother doesn't exactly put chills up my spine.
Dean: Benny, listen to me. Do not underestimate my little brother, okay? He can and will kill you given the chance.

8.13 Everybody Hates Hitler

Dean tells Sam to stop inquiring about how the Bunker works.

Sam: Yeah. I still can't figure out how we even have water... Or electricity.
Dean: Yep, well, I am putting that under the "ain't broke" column. Listen, little brother, let's not go all geek on this stuff, okay?

8.16 Remember the Titans

Dean asks Castiel to look out for Sam.

Dean: Listen, you know I am not one for praying, 'cause in my book it's... It's the same as begging. But this is about Sam, so I need you to hear me. We are going into this deal blind... And I don't know what's ahead or what it's gonna bring for Sam. Now, he's covering pretty good, but I know that he is hurting, and this one was supposed to be on me. So, for all that we've been through, I'm asking you... You keep a lookout for my little brother, okay?

8.23 Sacrifice

Dean tells Sam he's going to be okay after collapsing when stopping the trials.

Dean: Sam? I got you, little brother. You're gonna be just fine.

9.18 Meta Fiction

Metatron Tells Dean he's not afraid of him and Sam.

Dean: Why are you doing this?
Metatron: Because I can. Because you and your little brother and your fine, feathered friend and all those secrets you've got locked away in your bunker can't stop me.

9.23 Do You Believe in Miracles?

Dean knocks Sam out to keep him away from his fight with Metatron.

Dean: Sorry, little brother. It's not your fight.

10.13 Halt & Catch Fire

Dean tells Sam he'd kill him if he drove the Impala after his death.

Dean: Alright, so big brother didn’t get along with little brother, was pissed that he was driving his baby. I get it.
Sam: What are you saying? If you died and I drove your car, you’d kill me?
Dean: If you stunk her up with tacquitos, probably.

11.08 Just My Imagination

Dean tells Reese that Sully isn't a bad guy because he took care of Sam when Dean wasn't able to.

Dean: Listen, I’ve seen more than my share of monsters. And I mean real monsters, bad. These guys? These are Sesame Street mother Teresas. But when I wasn’t there for my little brother, Sully was.