If you have been on this sub long enough you might know that many see their stutter as their worst enemy. A curse. The one thing in life that is holding them back. I do this too. And I think most people who are not well educated on stuttering don’t know this. I’m not saying your partner feels this way, but given the situation I think they do. If they were bullied, this might have triggered something. I was not bullied for my stutter, but I know that I would be hurt too if I was in their situation right now. So my advice is: They might be sad and hurt for a while. And they are in their full right to be. Also I don’t think they are mad at you, I know I wouldn’t be. Give them time. After the greiving is done they will come back to your arms, hug you and say everything is ok.