My SO does this sometimes and while I don't mind it at times, I didn't really enjoy it done all the time. I realized that I became sorta dependent on her to speak for me. After a while my anxiety when I was alone and had to talk increased, so I just mentioned to let me speak unless I was having a really bad day. Stuttering is almost like a anxiety/fear loop, the less you talk the more anxiety and fear you have of stuttering when you need to speak. That's just my experience with it, best of luck to you two :)