You hear so many people who do not speak Black dialect use the expression ‘up in here’. The question I have is how much of the semantic load pass across dialect borders? As John McWhorter explains, ‘up in here’ denotes or perhaps connotes a sense of great comfort for the speaker wherever “here” is. As he says, if you wife says she over talking to the handyman and refers to her location as “up in here”, you might want to investigate the relationship a bit closer.