Good on you day one.
I feel good for you and your girl.
Also, just remember that guys and lassies have 'thoughts' about lots of things, every day, you could say.
Lots of people fantasize and in doing so release the tension involved in these desires. I don't think I need to go into the nitty gritty, but you catch my drift.
Don't get hung up about this. Often desires seem bigger than they are, because they are 'out of bounds'. Just accept that there are things we wonder about but, there are much more important things that might be lost if we succumb to our base desire and whims.
Good luck.