Am I wrong?

So I’m 17 rn and in a serious relationship for the past 8 months. I’ve met his mum, his family know about me and I can imagine myself getting married to him. However, this is my first serious relationship and it’s difficult because I have a very flirty nature and I’m very outgoing and Dont shy away from other male attention. I’ve been cheated on and I would never want to put another person in that situation but I can’t deny that I do get crushes on other guys but when I asked for an open relationship he said no. I’m always in an inner battle of stop being a stupid hormonal teenager and wanting to entertain other guys when I have a lovely respectful boyfriend and the other side of me screaming I’m still very young and should be free to do whatever I want and that it’s still very early for me to settle anyways. The obvious answer might be to break up with him but it feels like I can’t be without him, and these other feelings don’t outweigh that I do love him. What do I do, is this normal and am I in the wrong?