And get your ass handed to you because it totally isn't obvious what you are planning to do when you smash your glass. Seriously what the fuck? How would you know what my intentions are? take you're pshyco analysis somewhere else kiddo , you have no idea who is on the other end of the line.. Are you threatening me, or bragging about your violent nature? How cute. Anyhow, imagine if you did break your glass, last time I checked a glass being smashed to pieces makes a very distinctive sound, one that attracts attention. The black guy looks at where the sound came from, and sees you staring at him with a broken glass in your hands, you ofc looking all "tough guy plz be scared of me". Even the dumbest human on earth can guess what your intentions are.