My cat has been hissing at my husband mostly lately. She has not been the friendliest of cats. We have only been married for a short while. She seemed to be OK with him and now she has gone backwards. She is almost 12 years old... any thoughts?

Animals can become jealous just like humans can.

I suspect your "baby" has noticed that the Husband is getting attention from you that used to be reserved for HER.

Maybe with a little more time, she will accept the new arrangement.

Let him be the one to wash out her bowls and fill them with food. He can also give her treats if she will eat them. I think I would keep his scent off her litter box... I would be afraid that she would get upset and stop using it if he cleaned it. Hope this helps.