all up on

(def 1) On top of, either in a literal or metaphorical sense.

(def 2) Pursuing or showing interest in.

(def 3) Imminent or present.

Cultural note: This phrase has received some popularity due to it's occasional use by the character Strong Bad on the Homestar Runner website.

Used to mean an encroachment of personal privacy or space, invited or uninvited. Some form of pressure, either physical or mental, i.e. a woman dancing really close to another guy; a landlord pressuring for rent.

Can be used to imply sexual interest, as in someone who is intensely flirting/mackin on someone else, either physically or figuratively. Implies intense or clear sexual interest and pursuit. Same as all over him, related to all up on his balls or all up in his business. Can be used for both genders (i.e. he was all up on her)

to be nosy; to annoyingly look at or comment about someone's food(how the food looks, smells... etc.); to ask who ask someone who they are on the phone with; to look over someone's shoulder when they are reading(books, magazines, computer screen... etc), to ask, comment, or pry into someone's personal life.
This phrase simply means that someone is bugging you about what is going on with you. The phrase is a playful way to tell someone to back off of you and to get out of your business.
This phrase is especially useful in the workplace where many people are in close quarters.

the act of satisfying another's deepest needs / physically supplying themselves to stimulate their comfort zones to the point of physical fruition .

Verb. The act of delving fully into an experience or setting, in a deep or otherwise radical fashion.

Noun. The utmost level of commitment to an activity.

The state of flirting with a man, especially one who has used the ab-abber. See Homestar Runner.

Excessively doing something.
A graving or lust.