When I get truly angry (rare) my stutter is reduced to nearly zero. Its all about not thinking about it for me. I've had some times in middle school and high school when I was ranting to my mom and just going off about something to her (not at her or about her) and she would just get this sort of smirk on her face and she'd say "you haven't stuttered at all this whole time." (Stuttering was a daily topic of discussion in our fam while I was in middle school and hs, so it was pretty normal to bring it up and discuss regularly).