Isn’t this a nice cat?
You pet the cat. You petted the cat. Passive-The cat is getting petted. The cat is being petted.
I know in some places you might hear that the cat is being stroked. In some other places, this might sound unusual. Stick with the verb ‘pet’.
Remember, your cat is also a pet. So you pet your pet. Don’t worry, English speakers will understand you.