Bisexual

Okay so I have a problem and need some advice. I love my current boyfriend dearly we've been together for four years and I would never do anything to hurt him, just to put that out there. Also, I am bisexual. I've never had any kind of sex with another woman before. The most i've done is a kiss. Now I know having sex with a woman will not determine my sexuality at all but I've been I guess you can say craving, it for a long time. Just to see how it is and to experience it. I brought up the topic of a threesome with my boyfriend but he isn't open for "sharing me" as he says. I fully respect his opinion but I just don't know what to do. This feeling isn't going away, I just need advice please.🤦🏼‍♀️