Since they are clearly getting a hard-on over it, I wouldn't call these kind of niceties "casual". "Disgusting" seems much more appropriate. It's one thing to quietly ogle someone and then go home and masturbate respectfully, quite another to expect that they should interact with you as part of your pathetic little fantasy-foreplay. It's not militant feminism, it's self-respect. Taking part in this kind of an exchange leaves you feeling dirty and devalued, unless you are completely oblivious. I advocate responding to this behavior in any way that seems appropriate as long as it isn't nice. Being "nice" and smiling at creepy old douchebags like this only serves to perpetuate the cycle, I don't care how big of a tip they leave you. It's not enough to make up for it. So yeah, asking old guys to stop being gross is one way of addressing it. But asking the young ladies to stop endorsing it seems a little more realistic, and effective IMO. All it takes is the courage to buck a social norm. You can do it ladies, let's make this shit real, not just a hashtag.

I only see comments numbered 4 and 5 - what happened to the first 3? I didn't know the 'Merc was in the habit of deleting comments.

As for the dusty old pervs, just add some laxative to their coffee. That'll get them "moving along" pretty quickly.