My Girlfriend wants to have with other people, but not have with me?

Hi, I'm a 17 year old guy, and I'm dating a 16 year old girl. She says that she wants to have "meaningless " with other people, and keep an emotional relationship with me, and not have with me. She says that having with someone she loves "repulses her". How can I deal with this situation? I love her, but at the same time, I know how bad it would make to know that, at any moment, she could be having with someone else. I don't think I'm ready for sex, but I know i'm not ready to be a cuckold, sex just means way too much to me. To me sex is a very the culmination of everything in a relationship, (and i've told her this) but she really doesn't seem to care. what I'm asking is, is there any way I can get this through to her that I would either like us to have an exclusive sexual relationship or none at all?