Possessive Siamese Problem
So, we have this awesome Siamese named Emo. Typical to the breed, he is totally obsessed with my boyfriend. My guy is the epicenter of his universe. He gets along with me really well, so no complaints there.
The problem is that when my boyfriend is around, he is aggressive towards our other cat. He has very clear territory lines drawn, with his territory being the rooms that my boyfriend spends a lot of time in. Poor Bebe is vanquished to rooms that we only pass through. She sits very obediently and watches us from those rooms (if she can even see us) and only comes in to seek affection when Emo is asleep in another room.
The thing is, they're buddies when my boyfriend isn't here. We'll come home and see them curled up together, and when I'm there and he's not, they coexist in the same space fairly well. But as soon as my boyfriend comes home, it's bad behavior time - chasing Bebe out of the room, mounting her and biting her neck (HARD), chewing on stuff, etc.
We've tried some stuff like giving them multiple levels, playing with them more, etc. and that has all helped... but the problem isn't just territorialism. It's not really even aggressive in an explosive way. It's more just a lot of anxious, negative energy that partially gets projected towards Bebe, and partially just towards his surroundings.
It's also worth noting that his energy level often spikes when my boyfriend leaves, too. The second the door shuts, he starts chewing. Window blind rods, wires, anything rubber.... so the act of leaving is upsetting to him. My boyfriend had cancer a couple of years ago, and he had to be gone for 6 months. He says that Emo didn't get really intensely possessive until after that.
Any suggestions on making Emo less insecure? He already gets SO much affection, so I don't know how to help him believe that we're not going anywhere.