Do i take another girl to prom as a friend?

[kyle]

My girlfriend and I have been dating around ten months. We have been bestfriends since we were little until she moved a few towns over. I was a kid so i didn't have Facebook or Twitter or even her phone number. But in eighth grade she found me and added me on Facebook. Since then we have grown extremely close and are dating. This year i am a junior and we have prom. My school has a rule that only STUDENTS can go to junior prom. She goes to a differet highschool so she cant go. I still want to go with a group of my friends. My girlfriend and I cant come to an agreement. She doesnt want me to go but i really want to go. She said i can go to hers instead of my own. But it wouldnt be the same. What should I do?