Oh my! That is quite a look you're getting, but ... even more compelling is the posture of the woman .. it's as if she's being chastised. They were in the middle of an argument when he noticed you? The man behind them seems connected to them in some way because his stare is similar to the older man's stare.
I like the interplay of the four people. Each has something different on her or his mind. I know you like pictures on the darker side but this is about 2/3 stop too dark for my taste. I would have cropped a little tighter on the right. What really bothers me about the picture is the out of focus background. Looks very artificial to me. I would have lightened the man and woman standing up to separate them a bit from the background.
The concatenation of stares is interesting...the coffee drinker at you...the mustachioed man at the coffee drinker.... the handsome woman at the far extreme of the DOF at the mustachioed man...is there a narrative therein? Who knows, but they all were of that "moment"that you captured.