Let's see... With my roomie, it's the fact that, when she sleeps, she curls up a little and somehow always finds a way to rest her head on my chest. Plus she makes the cutest sounds as she does. For the youngest of my the girlfriends, it's definitely the fact that she has this spot, just above her tailbone, that gets her to squeak and kinda purr when I scratch at it. And for my other gf, she does this adorable thing whenever a game isn't going her way. EDIT: Forgot to mention how cute they are cuddling each other, also. EDIT 2: Alright, just to clarify things, yes they know about each other. It's a polyamorous relationship. If you don't know what that is, look it up.