One time my cat thought my boyfriend and I were fighting when we were just (trying to have) exciting sex. What happened: My boyfriend came home after a long day and essentially “attacked” me in a fun way; he grabbed me and threw me on the bed like “I’m taking you now!” I was surprised and sort of shrieked (I was definitely enjoying it, but the surprised sound obviously scared my cat, who was a super friendly, big male who loved everyone and was very social.) So the bf is on top of me and going to kiss me and the cat, who knew him well, jumps on his bald head and attacks him. Of course he immediately gets off of me because there’s a cat clawing into his head. I had to tell my poor cat that all was well and I was fine, and then he stopped. It ended up being hysterically funny. My boyfriend and I didn’t do anything like that again, for his own protection, and I learned then and there that I had a protective attack cat! Who knew? I miss him – he was a fantastic cat. My current (polydactyl!) cat doesn’t strike me as capable of the same — maybe I should test it? 😉
Source: Quora