You can hear him speaking, but you can't reply.
Your limbs won't move, your mouth can't speak.
Your mind is frozen in place, you can't respond.
You don't know what to say, how to open up.
You stare ahead silently, hating this feeling
Wishing he would stop and just leave you be
So you can breathe again and your mind will release you.
This is based off of my experiences with Asperger's. I sometimes have moments of selective mutism, like if I'm being questioned about schoolwork, where I just freeze in place and can't say anything. It doesn't happen often, but it's not fun when it does.