I've been in a handful of long term relationships (that itself is another conversation entirely) but for all of them I was actually the opposite. So, by the way you describe yourself in basically the male version of you. Often when I met new women (usually through apps), if I liked them I wouldn't stutter at all. Mainly though through active effort. So I'd be slightly mentally masking. Then, the more I saw them, the more I'd stutter as I simply "calmed down", and left the heightened state of composer since it's mentally draining to do that all the time. On the other hand, if I didn't vibe with someone. I may actually stutter more. Saying that, I tend to always stuttering if I'm talikg to normal people I'm not hitting on. TLDR: the longer I'm with someone the more I stutter as I stop trying not to stutter