You know two people who stutter? I’m still looking for my first ;) Coming to your original question, I don’t know. Stutter can exaggerate low self esteem in some people, it does so for me. A lot of people already have self esteem issues and having a stutter that you are not at peace with can just make it so much worse. At times I have very strong feeling of guilt and ask myself why my wife is still with me. She can do so much better. And this is after she has repeatedly told me how much she loves me and how my stutter does not bother her. I still feel the shame sometimes when I stutter in public and she is there (after 5 years of marriage). I also feel this constant need to remind and ask her why she is with me is actually harming our relationship. After some therapy I’m a little more at ease. Maybe you can suggest some general therapy to your partner. I’m not talking about therapy for stuttering specifically but general therapy for mood and self esteem.