There is no universal reason why some individuals may find this appealing. However, it could be linked to a specific fetish known as omorashi, which involves arousal from having a full bladder or wetting oneself. This fetish is a complex and individual preference that can vary greatly among individuals. It is important to remember that all individuals have different preferences and desires, and it is essential to prioritize mutual consent and respect in any intimate relationship.
Depends on how much you need a pee..... And, I add: when you urinate after needing to for awhile, your body releases endorphins and even a rush of serotonin, because distress and the biological processes involved in maintaining urinary continence both arouse the sympathetic nervous system and send cortisol and adrenaline into the blood. But "holding it" isn't a good idea; it can cause kidney infections and other health problems.