Why was I smiling?

So... I just found out I'm DID a couple weeks ago. I just had this experience where my husband was overwhelming me and causing me to dissociate. He can be really insistent and wouldn't let it go, but I couldn't explain how I was feeling. I was really upset and angry and dissociating really bad.

Out of nowhere I started smiling... But I don't know why because I wasn't happy. It was a wildly inappropriate reaction and truly felt psychotic. But I couldn't stop smiling for a good 10 seconds or more. Maybe even 30 seconds.

Why did this happen? I was actually really upset.