RMB stands for - Rolling my brain. It’s taking rolling your eyes to the extreme. When someone says RMB they are so done with the subject/situation that their brain is literally cringing and rolling back.
Argh this creepy guy won’t stop messaging me, RMB!
Acronym for Ring My Bell To show that you are delighted, pleased, or glad over a particular action that someone did to/for you; to be excited by something.