Haiktastic
Your mouth becomes a big O so wide it could fit a pizza inside and you're too dumb to shut it.
When my dad said he was going to retire and I was like 'no way' and my mouth wouldn't shut.
I saw a guy fall off a cliff and my mouth just went O for like five minutes.
My teacher asked me a question I didn't know the answer to and I just stood there with my mouth open like a fish.
xs