Superficial agreement to an action the speaker has no intention of carrying out.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.

...when an asian girl opens her legs, and a gong sounds to signify that her vagina opens horizontally, then it smiles at you to let you know that you are invited inside, but remember to take your shoes off so you do not offend her customs

when you slit the corners of a persons mouth then stab them in the thigh so they're mouth opens wide and their smile stretches back to their jaw.