Bro... I’m 35. I’ve been through similar shit. When I was younger I’d blow it up and end it. But I’ve learned over the years that this girl isn’t unique. She’s not a hoe or whatever.... she’s a girl. Im telling you now that you will never meet a girl that isn’t talking to or already fucking multiple guys. I can tell you’re young so here’s some wisdom. Shrug your fucking shoulders and say so what. Don’t even bring it up. This should be freeing for you. most schmuck ass dudes don’t even learn about this kinda shit until like a year in. And they’ve already given their commitment to a girl that never deserved it just because she’s hot. So chill out, have fun, let it be casual. Give her less time and effort and redirect it toward improving yourself physically, financially, and socially and toward other girls. Once or twice a week take her out, have fun, fuck her brains out, dip out (“i gotta get up early to lift”), let her do what she wants, and let her think she’s playing you. Be the dude the other schmucks in her life sorry about. Keep it casual. Accept that shes fuck buddy material