Pissed off. Literally.

So I've had my cat for years now. Five-ish years now? He has suddenly felt the need to pee on the floor, in my shoes, or other places that are not his litterbox. Normally, this only occurs when his litter box is full. But lately, it's been increasing in its frequency, and his litter box is certainly not too dirty.

I need ideas here to get this stop, so I'm reaching out to you blogging community. WHY is this happening and what can I do to get to stop? I've changed the litter type 3 times now. So it's not the type of litter. And he's sneaky and only does it when we're gone or not watching, so I can't catch him in the act.

Smart little effer.