The first time I ever romantically hung out with my now-wife, I told her I stuttered. She actually didn’t believe me at first because at that point in my life, I was pretty fluent. Over 11 years later, I stutter a lot more now than I did back then (something I’d like to work on) but it hasn’t made a difference in our relationship. Try being less covert and see what happens. If he really cares about what you have to say, he will support you in your struggle to express yourself more intentionally.