Have you ever wondered how it will be, if and when, you meet your boyfriend's ex? Have you wondered the right things to say, the right things to do and how to act?
1. You can be nice. Keep in mind that you have him right now, she doesn't, so there is no reason to be snippy.
2. Sizing her up will get you nowhere. Sometimes there is no rhyme or reason for chemistry. If you are scratching your head in disbelief that he was into her and now he's into you, don't bother, you will never be able to figure it out.
3. Don't do the old contrast and compare because chances are, this will just make you feel insecure. Just feel confident about who you are and the connection that the two of you are having in the present.