Here I'll explain some inside jokes for the fun of it :)

I'll categorize them with the person I made them with.

Best

Blaming Bellatrix

So I don't really remember why we started blaming her. But we do. It's our thing. I remember the first thing we ever blamed her for was for global warming, and it exploded from there. No offense intended, u Death Eaters can blame Arthur all u like...We all know who's to blame ;D

Yupo

So yupo is basically just a typo Best made. She meant to say yupp, but she zei yupo. I decided it was the new spelling of the word. We still use it in everyday conversation....