Hi guest, feeling like you do is quite common but it is not the way to build a healthy relationship. A lot of men and boys grow up believing they should be the only person their girlfriend had ever dated yet have dated a lit themselves. It is important to realise that her past relationships will only affect your relationship with her if you let them. Jealousy about this will destroy your relationship. she is not damaged or a s**t or less committed to you because she had previously had a boyfriend. She is normal. Your relationship with her started when you started dating. She is ok with your previous girlfriends. You need to give her the same respect. If you can't do that you need to get premarital counselling. Dont take this anger into your relationship. It will destroy it. You don't own her or her sexuality. You need to approach marriage as equal and respected partners. you can expect that she won't cheat on you. But having a boyfriend in the past is no sign that you can't trust her in the future. Trust her based on her action now, not on het past. She is not judging you. Make sure you don't take your jealousy into your marriage. You have no right to control her. Controlling behaviour and jealousy are toxic to a marriage. Marriage is a life long commitment. Dont jump in lightly. muster up some courage (I'm sure you have plenty of that) and get counselling for this if it is really bothering you. If she is worth marrying then she is worth getting counselling for do that you can start your marriage off as a happy, loving, trusting couple.