Hi KGirl,
I have had some of the same issues. WAH posted photos of his new house on FB and some of my friends (mutual friends, but really my friends) commented congratulating him/us. I wondered, should I email them and say I didn't move, he did...? I just did not feel like it so I let it go. Eventually someone told them.

If you want to post pics of your cat, do so. When/if people comment you have many choices.
1. ignore the comment (like the comment if you want but don't answer it)
2. message the person directly
3. say something about H being with the other cat

And you can make these choices for each individual. When I saw one friend liking and commenting on WAH's facebook, I sent her a message telling her the "news" because she was MY friend and I knew she would want to know. What did she do? Immediately deleted her comments and unfriended him. ha.

So it's up to you but I say just go about your business and don't worry too much about the comments and questions. You can ignore them. If people are really wondering they will contact you directly.

Hugs, Lisa