Has it been a long time since he was neutered? How old is he? Please tell us a little bit more about him!
Does he pee in “weird” spots, like outside his litterbox(es)? Small amounts of pee in many places? Have you seen him strain to pee or dribble pee a little here and there?
If he’s been neutered quite some time and he seems “incontinent” and it’s an ongoing thing, I’d suspect a UTI or E cuniculi affecting his urinary tract.
The urine needs to be cleaned off and patted dry -if it’s just stains they can sometimes be brushed out dry with corn starch. But if his legs gets wet with pee, he needs to be cleaned with water (“butt bath”, not full bath) or it will lead to fur loss and weakening of the skin barrier, which can create the perfect breeding ground for bacteria and fungi. He will probably not be over-joyed, at least not the first few times, but there are ways to make a butt bath at least somewhat acceptable.