A slang term usually uttered in the South..more specifically in the South....most assuredly in Texas..mainly in Houston and almost always by Chuck Savage. It is used as a verb to describe anything going into the body, food...beverages...even sex. Anything that can be inserted into any oriface.
Walter asked the young men to go eat dinner with him and get some supper all-up-off-inya. The young man declined the invitation.
girl : Hey where are you going tonight?
guy : upinya
girl : where’s that? I’ve never been there?
guy : Oh you’ll see
annoying guy: (with pencil in hand) excuse me do you know where the pencil sharpener is?
guy 2 : Why yes I do, I believe it is upinya.
annoying guy: Oh then will you be a deer and point me in that direction?
guy 2: NO! Now go f@#k yourself