You also need to see the situation from both sides I think. Although you perceive that Cleo was only sitting there "innocently" what Triton saw was another cat staring at him... which staring is a threat in kitty language, and he had a toy he was enjoying and wanted to keep. Children are VERY possessive of their toys, you should share with them but there will be a tantrum if you try to take "their" toy away...
Maybe you can put a screen door on that door to the playroom so that there is more visibility of the other cat while playing or eating, but in a safe manner?
Maybe you can put a screen door on that door to the playroom so that there is more visibility of the other cat while playing or eating, but in a safe manner?
