I might add one small thing…
If a girl wants to have sex with you, she jumps at it. If she wants a serious relationship with you, often she will pretend to be hesitant at first. Then give you a little feel or something at the end of the evening to encourage you for the next time.
Me personally, if I don’t want a serious relationship, I will talk about friends and how serious relationships are hard to judge in advance. All are good points and true. At that point you have been honest and straightforward, and you can go for it without apology.
Great post, thanks for writing.