More to update: We used to have three litter boxes for four cats, but had to go to two when my brother-in-law moved in with us. I set up the third box again (Don Juan's old box) on the balcony. We can't have it in the bedroom because of my husband's asthma, and no place else to put it.

Don Juan is spending a lot of time on the balcony. I have food and water out there for him, and leave the door to the bedroom open so he can come in when he wants.

I think he may be having an issue with my husband's boy cat, Rugger. Rugger likes lots of attention, but is not cuddly.

We are, of course, looking into better arrangements.