Do women like men jerking off watching them doing normal day to day activities?
Since we've established this will be some "random guy", that is, a depraved stranger/fucking weirdo, I offer the following scenario and response.
Scenario: I'm ordering coffee at a local cafe when suddenly a man walks in, takes out his penis, and begins masturbating whilst eyeing me.
Response: I take out my phone and begin recording him. Shortly after obtaining video evidence I scream at the degenerate to "get the fuck away from me!" as I retrieve my pepper spray and then empty it into his perverted face. I then retreat a safe distance away and immediately call police speaking loudly enough so that everyone in my orbit knows what the offending piece of perverted dog shit did.
... Calmly sip my coffee, eyes locked on the weirdo, wait for police, sip coffee, wait ...
If he decides to make a move in my direction at anytime he is in for some hot coffee hell and or combination of kicks to his groin. If he decides to leave I will follow him from a safe distance all the while talking and giving direction to police on my phone as well as telling everyone who crosses our path what the pervert did and that police are en route. With any luck a couple of dudes will tackle his sick ass and keep him subdued till officers arrive.
Mike, don't be that "random guy". Being on the sex offender registry is no way to go through life.