What actions make you shudder?

A while ago I posted a question asking what words/phrases make your skin crawl when you hear ppl say them. The replies gave me endless entertainment. For me its a grown adult clapping their hands while saying "yay" to express their excitement.

Or colleagues that visibly suck up to management.. its vomit inducing!

Also, people who constantly talk down about their "friends" behind their back but then post pics of them online saying "drinks with this one again". Have some integrity!