Help, I Stupidly Introduced the Wrong Lady to My Parents

I am in my mid 20s, so also is my girlfriend and we have dated for eight years though most of it was a distance relationship but everything was just okay. She is very nice and faithful and she loves me. I know and I thought I loved her and I was even planning to introduce her to my family because allthe while we have been dating, she has never met my parents.

Then recently I met another girl who really touched my heart and I started an affair with her though nothing serious to me, I thought she was just someone to screw around while my girlfriend is not around.

After some weeks by accident I met my parents and I happened to be with this new girl. As it turned out, my parents liked her immediately they saw her because she’s very beautiful. I don’t know what came over me and I introduced her to my parents as my girlfriend and they seemed pleased.

My parents are very strict when it comes to relationships and always warned us that we should never go into a relationship if we do not have a serious intention of settling down with that person.

The issue now is that I don’t want to disappoint my parents by introducing another girl after telling them this new girl is my girlfriend. But that my old girl is the one I think I really want to marry, but how do I go back and tell my parents? Or should I just try to get serious with the new girl and leave my old girl? I’m just so confused.