I became addicted to her fucking and sucking after the first time it happened. I'm not sure if I'm addicted to watching her or if it's the sloppy seconds that follows. Even when I'm not sharing her I love to watch videos of her in action to study the expression on her face as things happen.
For example, I've noticed that although she doesn't like me to cum in her mouth, when she sucks my brother she seems to be trying really hard to make him cum to the extent that if she can't do it just by sucking it she will masturbate him as she sucks. When that happens she says something like, "You're not supposed to do that" but as she says it I can see the smug look on her face.