1. Let Me Know
2. Lick My Knuts
"Just LMK if I can help you out"
"Just LMK if that will help"
Let me know
What do you think? LMK...
It simply means "let me know." Or get back to me with answer.
If it already formally exists, I don't know, but I started using it in my e-mails in the '90s for convenience. Today, someone responded "OH!!!!!!" after I replied to his "what's the meaning of that" e-mail. So, there you have it.
In e-mail commonly, consider for example:
1) If you need anything, LMK.
2) What're you guys doing tonight? LMK.
Means Lick My Kitten, Kitten being slang for the female genetalia, this term would be used in the same context by a female that a male world use the phrase "Suck my dick" in
Guy: what's that mean
Girl: lick my kitten
1. Launched my Kitten
2. Lick my Klit
What did you do today?
Hey could you LMK?
Username: I just got a million dollars.
James: LMK! LMK!