I don't get what the problem is. Are you saying that you are worried that your girl "might" at some point cheat on you? Well, stop worrying because she will, you and her just don't know who and where it will happen. What you have to do is to make sure that you are not hurt by it when when she or he finally reveals it to you accidentally in the future.
Hot girls cheat on their average guy boyfriends. Deal with it, move on. Since you are now a DJ and are adept at finding hot chics (well, you are, aren't you?) then it should be no problem replacing this one as soon as you find a newer model.
The key here, as it seems to have always been, is to simply make sure that you are a desirable male. Once you do this and realize it, the scale tips in your favor as far as cheating and worrying about it.
If it was my GF-- I would just get another one. Seriously. Even if she never cheated on you at any time, the fact that you even worried about it is grounds enough to dispose of the entire thing and find a better one.
My current GF won't cheat on me, not because of anything I learned from this forum, but simply because she knows that she can be easily replaced in about 10 minutes while I can't be. She is aware of my ability to pick up hot girls without even trying, and lives in constant fear that if she takes ONE misstep, I will bail.
But maybe this is a good time for you to learn a lesson without anyone telling you what to do. Thats how I learned.