Seems like you've been working hard to influence your GF’s preferences, but, honestly, you can't really change someone's comfort level overnight. Some people just aren't into certain things, and that's fine. The important part is respecting her boundaries and what makes her comfortable. Building confidence can take time, especially when it comes to something personal like this. If she's warming up to the idea gradually, great! But pushing too much might just make it feel forced. Give it some space and let her find her own groove with it.