In a more civilized time, this would result in a shooting and a quick burial

 Man masturbates in public near a woman, and then slashes the woman's husband after the hubs tells the pervert to cut it out.

A vagrant slashed another man who confronted him for masturbating in front of his wife outside Penn Station late Wednesday, according to cops and police sources. 

The unidentified 21-year-old suspect – who is listed as a “John Doe” in police records – was pleasuring himself near the married couple at the corner of West 34th Street and Seventh Avenue around 11:20 p.m., according to cops and police sources. 

The proper response to some pervert wacking off in public and then trying to cut you is shooting him until he stops moving.  Mental illness or drug use, whatever is making this person do what he did, I don't care.  He's a threat to society.  And if the people who are charged with protecting society refuse to do so, then the pervert goes back to ambient temperature as law-abiding citizens take care of the problem.

Of course, this being New York Fucking City, the population there has elected dictators and tyrants who have disarmed them, and the sheep willingly gave up their guns, so they're screwed.  Enjoy the hobos jacking off next to your wives and kids.  You deserve it, especially after you elected de Bolshevik multiple times.