touch my pearls
You are engaged in conversation so your reaction towards something or someone that has impressed you. In a lady like way, our reaction is to "touch my pearls" in a manner that shows you've been impressed.
During conversation or showing that you're impressed. So you use the comment of " let me clutch my pearls or touch my pearls". Or it can have an opposite effect and you comment " let me clutch my pearls" because you're not impressed.