A diaper is a piece of cloth, or a pair of paper pants. Most folks do not find those things sexy, but some of us do. If a hot gal (or guy) is even sexier in a diaper, you have a mild diaper fetish....
You can't, really. You can only have a heart-to-heart talk about what you want, and let her do what she's comfortable with. If this isn't enough, it appears the fetish is more important to you than...