So... what? the joke is that because he couldn't find an old sock to deliver the money in (and since when is that the default choice?) he had to transport the money some other way... a gooey and smelly way if that stuff splattered on the 2nd guy and his facial expression is any clue. Not sure I want to know where.
This is a pretty unclear comic.
Came into some old money is the real play on words here. The sock bit is just thrown in so the reader is clear what the play on words is referencing. Otherwise the reader would just assume it's snot and not tie it back to masturbation.
This is a pretty unclear comic.