It could be, most likely, 1 of 4 things.
1) Severe Scrotal / Penile Edema. Think about a pumping doughnut ring, that is your entire genitalia, and never goes way, but in fact increases little by little every day. They have decreased circulation and lymphatic flow, thus the fluid builds up. In the hospital, we actually do what is called a "Bellvue Bridge", to keep the genitals elevated above the level of the heart in some of these convalescent patients.
2) The could be wearing a 'leg bag' and / or a 'texas rig'. For guys who are incontinent (can't control their bladder), they may have a urinary catheter in their penis, or a 'condom cath' / 'texas rig' that drains into a bag strapped to their leg.
3)It could be that they are wearing absorbent undergarment for urinary incontinence.
4) It could be a very severe hernia and / or hernia truss (supportive garment)
I see all of these types of things fairly often in the older patients that I take care of.