all signs kitty has had enough, and time to back off. A cat
that is in pain may suddenly bite, also. All cats
are different, though. We can pet and love on Jade forever, but we have a neighbor cat who will seek us out for loving, seem all cool with it, but literally for ONE minute, then she will bite and turn on you! It's all in how much tolerance a cat has for petting/stimulation.
You might want to google 'signs a cat is going to bite'..