“lmk” Text Meaning

"Let me know" — puts the ball in your court. They are interested enough to ask.

From a guy, "lmk" is typically literal slang — guys adopt texting slang for speed and in-group ease, not hidden meaning. If there is subtext, it will be visible in what surrounds it, not in the abbreviation itself.

From a girl, "lmk" is also mostly literal — but girls more often use slang to set tone: playful, casual, unbothered. If her slang level with you is different from her formal style elsewhere, she is choosing the register she wants with you.

Match the energy and keep the exchange moving. Slang is casual by design, so a casual, quick reply fits better than a formal one.