Yes, she knows you have had intimate moments with other women, but every woman wants to think she is the only one. Saying an ex’s name during sex blasts can destroy those illusions, blow her mind out of control and bring up certain questions, like, “Do you think about her while you are having sex with me?” and “Do you wish you were with her?”
If you make this huge mistake, be extremely apologetic and be prepared to do whatever it takes to prove to her that she's the most beautiful, intelligent and sexiest woman you have ever met. You'll have to prove to her that it was an honest mistake, that she is the only one for you and that you don’t think about anyone else but her until she forgives you.