Now CJ can approach the bum and give him some change. The bum can go after that to thump, and it is quite possible that he will vomit. And a homeless person can get poisoned by low-quality alcohol and die. Also, if it is a "noble bum", then he will get a knife and be your faithful companion.
Usage: Approach the bum and press the English "T" (maybe a couple of times).
Only works when the player is not completing missions.