I didn't know what it was when I first got on here either, and I saw when someone else asked the question and I got the answer. I tried to google it before then too! Lol.
I always thought is was an inside joke too and was to embarrassed to ask so I googled it lol
So glad you asked this. Lol.
Lol I thought it was some inside pregnancy joke or something. Clearly I over thought this one
We say bump because when you comment on a post it "bumps" it back to the top. Sometimes you will get more answers.
Lol so your question can go back to the top of all the questions