Look... One needs to have trust in a relationship. For a relationship to work and last, both of you need to have trust for each other. Why don't you sit down and talk for your future without being emotional and see what is the problem. It is better to talk now before getting married to rectify the differences than after getting married. That is why we called this period as engagement period.

Maybe she don't like the way you treated her.. or May be this is the sign for you ... that she is not meant for you and you probably deserve someone better. Look at the positive side of it. Ask yourself why you want to marry her? her beauty or her personality... If it is for her beauty, it will fade one day but personality will live in her and will treat you well... Good Luck mate. It is not worth it to do this spying activities.... You are a man ... come on...