Dear Parking Dude:
I know that you don't make much money working as a surface parking lot attendent (perhaps you were even homeless/on meth), but given that you look at least a few years younger than me I expect better behavior. Next time don't flag me down on the sidewalk as I am leaving work just so that you can ask me if I'm going to finish my cold, black, Starbucks coffee.
I could understand such behavior from a senile Great Depression or senile WWII survivor, but not from someone who looks like they were born in the late 1980s or early 90s. Plus, it's generally not good hygine to flag down a random guy on the street and ask to finish his cup of coffee. Despite it all, I probably would have given you my half-empty coffee cup if I thought it would give you some nutrition, but alas, black coffee has no calories and is acidic enough to make hunger worse.
P.S. You did not look too bad. If you grew a beard and were willing to move to Ontario, there may be a guy there with a hair fetish that will gladly make you fresh coffee - with cream and sugar - in return for certain, verboten, services.
Sincerly,
The black dude who did not give you his coffee.