Thinking of sex with other people??

So hopefully no judgement here but I’ve been in a relationship for 3 years. Before we got together I never dated anybody else, kissed anybody else, & I was a virgin. Meanwhile my SO had his time around town with other people. I’m going to college and I wonder if I’m making the right decision by staying with him. He is truly the love of my life and wants to marry me- our relationship is beyond perfect. But, I’ve been thinking that I’ve never had the experience of being with other people intimately. I’ll never be able to experience a hook up, etc. not like that’s super ideal but in college you kinda can just be tie free and do whatever. I’m wondering if when I’m older and do get engaged to my boyfriend I’ll regret it. In other words I’ve never had my time to hoe around I guess you can say so I wonder what it’s like 😂 but I also love my boyfriend dearly and don’t want to let him go. We’re in a long distance relationship so I’m wondering if I’ll start to think of sex with other people when away. Any thoughts or similar circumstances? Thanks!