Chara and Ojirou call Mineta M&M from time to time because his initials are MM (his first name is Minoru for anyone who doesn't know)

Backstory for this headcannon

"M&M! Get in here! We're going to Loo Loo Land!"

...

"Loo Loo Land?"

*smash*

"LOO LOO LAND!?"

"TO LOO LOO LAND!"

"SHUT THE FUCK UP!!!"

If ya know it, ya know it, if ya don't, ya don't.