If your suspicions are true, and you actually can control Kristen's thoughts while you're her panties, this opens up a whole new world of possibilities. You could play with her like a toy. A giant toy who was a person just a few moments ago, just like you're a pair of panties that was a person a short time ago.
You decide not to get ahead of yourself, though. Let's test and make sure this works. You decide to start thinking hard about a thought that's totally out of context, so that it can't be a coincidence if Kristen says...
"You know what?", she says out loud. You can feel her voice vibrating around you, mixing with the scent of her pussy, and you still love it. "What I really want right now is a beer. Go and get me a beer."
It worked! You're interrupting their tender, heart-to-heart conversation by having Kristen demand that Kevin get her a beer. And it's still morning, so it doesn't make any sense. And that's exactly what you thought! This is amazing.
And Kevin goes along with it! He seems shocked by the request, but apparently in the interest of keeping his girlfriend, he's going along with it. A minute later he's back with a beer, which Kristen starts to drink. That's better.