I am sure we have all found ourselves in a situation where we are engaged in a conversation with someone who has no concept of what your private space might entail. As they talk they get closer and closer to your face until you feel their breath on your face, yet not in the romantic sense, not in the least. You keep gently taking a step or two back, but to no avail for they keep coming at you, invading the personal sphere you have around you, which, until this instant, you wrongly assumed was acknowledged by all in the invisible and polite sense.
Yet, this person has no concept as to the few inches your reserve for free ranging and roaming particles. Rather this person seems to think that in order to converse with someone, you must have your faces as close as possible without actually locking lips. Now, I don't care how loud the venue or bar you are situated in is, this amount of closeness is not at all necessary for exchanges of words, ideas, and laughs. I am only left to wonder as to why they cannot seem to gauge the personal clean air breathing space I had reserved prior to meeting them, while I have taken so many steps backwards that I am now up against a wall and trapped by an mouth with an endless motor, which keeps moving far to near as a sense of claustrophobia sets in.
You cannot deny having had this experience, and if you can, then I suggest you take a step back from the partner you are involved in friendly banter with.