I remember you saying that his bum was sore and elimination was painful for him, maybe he has learned to associate the litter box with pain and is looking for a softer more comfortable spot to go. That said I have had problems with Maya that i now think were stress related due to changes of routine, strangers in the house etc. The vet gave her a clean bill of health and some anti anxiety meds plus Feliway and that seemed to settle it. Oh yes, I make sure I'm home by 7 pm at the latest. It doesn't matter that my husband is here, it has to be me that touches base with her and then I can leave again. We've had no peeing since January . I used that Miracle pet stain remover stuff, it has a mild peroxide solution that took out peestain and smell from my comforter, pillow and futon couch and bed. She left no spot unpeed that was associated with me.