Hi, you may be describing exhibitionistic disorder, which is a condition marked by the urge, fantasy, or act of exposing one’s genitals to non-consenting people. If someone you care about may have an exhibitionistic disorder, early treatment is strongly advised. Treatment for exhibitionism typically includes psychotherapy and medication.

The following articles discuss symptoms, causes and treatment:
- https://www.psychologytoday.com/us/conditions/exhibitionism
- https://www.merckmanuals.com/home/mental-health-disorders/paraphilias-and-paraphilic-disorders/exhibitionism
- https://courses.lumenlearning.com/atd-herkimer-abnormalpsych/chapter/exhibitionism-302-4/

The prognosis for people with exhibition disorder depends on a number of factors, so it does not seem appropriate to offer advice. Hopefully reading these articles will help you decide whether to continue to try to help your friend seek and receive treatment before he is caught and required to do so by authorities.

I hope this information is helpful.