Inter-faith relationship advice. Honest opinions only.

Hey there! I (23m) have fallen in love with a girl (24f) that happens to be Jewish. We have been dating for almost 2 years and the amazing rush of first being together has never worn off. We are both so perfectly compatible even with our differences. I would like to propose to her soon and I’m 100% sure she would say yes but the problem is her Jewish parents don’t like me. They never have. My girlfriend denied it at first but then said they are just like that with any boy that takes an interest in her. it was important to me to get her fathers blessing so I knew it was something I had to just deal with eventually. I finally worked up the courage to talk to him today. I pulled him aside and very respectfully asked why it seemed like there is tension between me, him and his wife, I told him there was no hard feelings and I wanted him to be honest with me. I told him that I loved his daughter very much and that I wanted to address problems and correct myself for them if I could. He told me they have no problem at all with the way I act or who I am. He told me in fact they quite like me as a person, however he said the reason they cannot accept me as their daughters partner is because I’m not Jewish. He told me that they could never allow their daughter to be married to a non Jewish person as it is forbidden. I explained to him that I would never disrespect her faith or lead her away from Judaism and i told him I would also attend services along with their family if it made it better. He told me that the only way I would be accepted into the family is if I converted to Judaism. I told him that I didn’t want to lie to him by promising him I would. He told me that he can never give me his blessing until I fully and honestly convert. I don’t know what to think or do? Should I move forward with the proposal anyways? Should I keep trying to reason with her mom and dad? Should I ignore his wishes and possibly put my girlfriends relationship with her parents at stake as well? Giving her up isn’t an option to me and I don’t fully understand why her being in a very happy interfaith marriage is such a huge deal.