Yeah I have noticed that too. I do nothing differently, I don’t pressure I just ask if she needs anything to feel more comfortable. Sometimes they are on their period and want to go to the bathroom first before. But it does seem that if they get embarrassed that they were not ready to have sex even if they like you they will shy away. Or they just were being nice to the point of almost sex, but they really were never going to go there, but thanks for the free meal and drinks ;)
