An expandable pee container in the lower abdomen made to contain drops of urine until a nerve response says it is time to piss the accumulation and not too many hours until you will be desperate and can't hold any more or can't pee at all and are in pain because your bladder is bashful. The sack's normal hold is about 500 mg (1 pint). Upper levels vary all the way from 750 mg to 2000 mg. So some lucky people get to pee only once a day and the rest of us 4 or 5 times a day.
The question is who has the largest bladder, men or women, gay or straight?