You don't need to discuss it with her at all. I would just assume that she "forgot" something so she could get to see you again. It happens all the time, girls forget or leave things as an excuse. That means she is into you. Who cares if you didn't f*ck her straight away, it's not that big of a deal. It probably made her think about f*cking you after. girls are like that, you planted the seed of...em planting your seed and she marinates on that and after a while she probably wants to seal the deal. You just have to chill out, have some wine with her, start kissing her and move things to sex. YOU DO NOT AT ALL HAVE TO ADDRESS THE OTHER NIGHT! She may even be thinking about how much of a tease / challenge you were for getting her all turned on and then stopping, and she wants revenge sex!!!! If you bring it up, she'll switch to "Wait a minute, you mean you were SCARED??? oh god I'M THE ONE WHO IS SUPPOSED TO BE UNSURE, NOT YOU..what a turn off!!!" - Why even open up the possibility of that happening at all?