Most times escorts don't answer their phone is because they are busy, a good sign, and they fact they don't answer their phone when thay are busy or otherwise engaged is another good sign.......
But I must admit, I have this problem sometimes.........
If you phone an escort you want to see, and she doesn't answer, you leave it a while and try again, she still doesn't answer, I'm left wondering, is she still busy??? And if she is, and I phone again, and she still doesn't answer, how many missed calls from the same number starts to make it look desperate???