I'm currently in a relationship with a girl who I love and who loves me. But sometimes I do wish I could have the excitement of doing things with other people. I don't allow my eyes to linger on anyone I find attractive who I see in the streets or online. I feel like I want the freedom to do sexual things with other people, but it would hurt me if my partner did it too. Obviously this isn't fair and isn't a viable scenario for any functional relationship. But I don't know what I actually want, and what's just an Impulsive kind of desire? I once ended a relationship because I wanted the freedom to smoke pot and my gf at the time wasn't having it. I also wanted the freedom to be with other people. But when it ended I was just heartbroken and uninterested in actually being with anyone. And I never even stopped loving that girl and later regretted leaving her. But I'm worried that if I don't give into this desire and I just 'repress it' aka not act on it, then in 20 years I'll just break my gf's heart, or destroy my family and my kids.

Has anyone been in a similar scenario and get what I'm talking about?

I've asked my gf for a few days to think on the matter. I've told her that for moral reasons I'd never cheat on her no matter what, but obviously that's not sustainable because of the repression thing I mentioned earlier. What do you guys think? Is this just BPD impulsiveness and pleasure seeking? Or is it a genuine thing that I'm just not someone who wants to stay monogamous?