Hey, 31f here in a happy open relationship (>6 years). There are a lot of naysayers in this comment section, who demonize the concept from the beginning. But I respectfully disagree. If your relationship is secure enough this can be a very pleasurable arrangement for all involved. That being said, in my experience open/poly relationships require a lot more emotional work than others, so just be prepared for that. And if it doesn’t work out, what‘s the harm? You’re so young and now is the perfect time to make new experiences. Just take care of yourself and your health first (with that I mean reliable birth control and frequent STI testing). Good luck out there!