I'm living with friends, with my cat, and their cat doesn't like it (me or my cat). Long story short, she keep skulking around because I have Mr. Purr out of his captivity (cativity?), on the couch with me, and every time she goes by, I make a popping noise with my mouth, then proceed to giggle as she jumps.
She's going to murder me in my sleep.
Update: Sony's personality in a nutshell. Adorable but will destroy you in a heartbeat.