- Harley has a different reaction to people saying ILY to him than most people because of abandonment issues as a child, example: 

Tony(at end of call): Kay bye I love you don't do anything stupid

Harley (now standing there frozen trying to mentally prepare himself): what do want from me.

Tony (concerned): kid? I just said I love you??? what?

Harley: you  want something from me that's what people say when they want something from you dammit 

Tony: no kid that's like abusive and manipulative 

Harley: what does that mean? I'm confused wait...

Tony: Jesus Christ I'm getting you a therapist

 - He also is really clumsy and can't catch stuff for the life of him

- Harley can't sleep alone any more common for you to find him curled like a cat a the end of Tony and Peppers bed

- Harley can't stay still very long so his entry card  to the tower photo is actually a blurry picture of him sledding on Captain America's shield... in the dead of Summer... on a staircase

- Nicknames for people:

Peter: Darlin

Mj: MJ (because he would die a fiery death otherwise)

Ned: Ned my man

Tony: Old Man

Pepper: Bell Pepper or Salt and Pepper

Shuri: shuriiiiiiiiiiiiiiiii