Inserting objects designed for it into the urethra for arousal and sexual pleasure

There are many toys and options available for this kink including electric stimulations.

The core is to have the prostrate in the urethra stimulated. You can layer this kink with other kinks

This kink is very risky and therefore requires training and prober tool management. If this kink interest you, please do plenty of research and try and locate someone who can train you in this. You should make sure yourself and your Play partner(s) have had the required introduction and training in how this works.