When someone calls a grown man, a boy or son. No matter if it’s slang in a friendly way, you respond with I got your your boy or son hanging. (Meaning your Dick hanging). The term is used to make sure that person never makes the mistake of calling you son or a boy again.
This means, everything you say is being thought over and absorbed by ther person reading or listening
if someone were to say, i'm hanging on your every word
it probablly means that they can't wait to hear what you are going to say and are basically looking for some possible other meaning to what you might have said.