This is for my industry associates who kick guys out of men’s Brazilian wax services if their bodies involuntarily respond in a socially awkward way …
Shaming a man who is already mortified by the unintentional erection he neither wants nor can keep from happening is both unprofessional and unreasonable.
Go back and reacquaint yourselves with Physiology 101 so you understand this is a visceral response to being touched anywhere on the body, not just the genitals (which is why it also happens during massage and facials).
They can no more prevent it than they can keep from shivering when cold or sweating when hot.
There is absolutely no question when a guy is being a perv and when he’s struggling with embarrassment over something he cannot control.
It’s your job to know the difference and act accordingly. If you don’t accept that reality, you set your clients up for an emotionally traumatic experience and shouldn’t even offer the service.