Just a quick one: Fun phone idea
Why not take a photo of the key on your person, be that an angle shot (like the photo below), an arm bracelet shot, a photo of your car keys in your hand with the key visible, or better yet a cleavage shot with the photo hanging in a suggestive and/or revealing position… then make it his phone’s home screen. Or perhaps make it the photo that shows when you call him, and give him a ring to say you love him at work?
Might want to check if he has meetings where people might see his phone, though there’s no better way for him to think of you all day if he has to hide his phone from everybody. Naturally he’s not allowed to take the photo off ’till you say so! After all, his dick and orgasms is not the only thing you own, is it? 🙂