Too scared to have sex with a woman 🤦‍♀️

So I’m in a wonderful relationship with a man. However I’ve been with him since I was 18, and for about a couple of years now I’ve realized that I’m bisexual. We’ve been together for 4 years and are engaged. I told him maybe a year ago that I could see myself as bisexual, but honestly only to have sex with a woman. I feel like in my life only a man could give me what I need long-term. However, I still want to have sex with a woman! I’ve expressed this to him, and he’s completely okay with it. Thinks it’s sexy even. However, I feel guilty for wanting to go out and have sex with a woman 😣. I’ve only ever been with him, and he’s really all I need, it’d just be nice to have sex with a woman. And I also don’t want it to be a “free pass” for him to have to have sex with someone else (because I’m selfish lol). We have a wonderful relationship and I don’t want to feel like I’m cheating on him. But I don’t want him to join either- at least not my first time so I can experience it myself and see how I like it.