So my girlfriend and I were playing around near the linen closet, our cat and kitten nearby, and I was trying to close the closet door on her and the cat came up and was persistent in trying to get into the closet through the crack so I opened the door, she hissed and proceeded to bite down on my girlfriend's arm. It was a quick chomp, drew a little blood, but then the cat just walked away and hung around us. I don't think she was being malicious, it just worried me that she hissed and then bit someone. She's been known on rare occasions to grab my leg and bunny kick it, but those times are so far and few in between. Her most recent heat cycle just ended so she's back to her normal, unaffectionate self. And I'm certain this wasn't the first time she was witness to us horse playing or making loud noises, and I really don't know what other reason she'd have to bite, especially when it is preceded by a hiss.
Any thoughts on what happened?