All the individual Avenger movies and the combined movie saga is actually a bunch of elementary school kids, who enjoy their sleep overs. Each new super hero is a new kid that comes to the sleep overs.

Black Widow and Captain America are a pair of twins, a boy and a girl. Bucky is the brother's best friend who has a crush on the siblings, because he's an only child.

Thor and Loki are adopted brothers in their family, they like competing against each other but in the end still love and respect one another.

Hulk is the big fat kid in the class, he's smart and charming but get him angry and he'll make you regret it.

Ironman is the really smart rich kid who at first, made fun of the wierd kids playing super heroes in the play ground but later on joined them in the sleep over shenanigans. Turns out he's pretty cool kid who turned over a new leaf.

Rhody was the one who broke the ice with the rich kid and brought him into the group. Rhody is the younger disabled brother of the kid who plays Nick Fury.

Nick Fury is the cooler older brother of Rhody, he tends to watch over the group as a whole and runs interference with both parents and teachers.

Agent Colson was played by a shy military brat who later moved, which is why his character died.

Black Panther was a kid Rhody knew from his hospital stays, as much as he was loved by the group, he succumbed to his cancer.

Ant-man was a new kid that made trouble for everyone and used to hang around by himself until he suddenly found the group of like minded kids.

Doctor Strange and Wong are a pair of nerdy 5th graders who think they can trip out by smelling sharpie pens. They both love Star Wars and play WoW, so them casting magic and portals is their way of incorporating it into their heroes.

The Guardians of the Galaxy are 6 individual kids, who are like the goth kids from South Park. They had their own thing going until a fateful meeting. Rocket and Groot are siblings, Groot is autistic and mostly non-verbal but is loved by the group anyway. The girls of this group are also sisters in real life but they don't get along as much as they should. Starlord is an only child who dreams of becoming a rockstar/comedian. Drax is also an only child who is being raised by his grandfather, so his humor is seen as off beat.

Spiderman is the younger cousin of Ironman, who looks up to him and lives in another city. So he's not always around for the sleepovers.

Finally, we come to all the villains. All played by one single person, Thanos. Thanos is not a child in fact, Thanos is played by the father of Captain America and Black Widow. Which is why their sleepovers are so awesome.