Cathying is most frequently found in Mom congregations around the internet. The act of overly explaining in an aggressive passionate and condescending snarky tone all at once in am effort to deliver the colloquial "mic drop" at the end.
Karen: I'm about to start Cathying the fuck out if McDonald's doesn't honor my coupons
Judith: If this bus driver shows up late one more time I'm going to start Cathying all over management and get free passes for a month
Cathy: My doctor was telling me they know more about the drugs best for me than I do even though I have googled all of them and know what works from years of trial and error and tramadol works best for me. Basically I was Cathying so hard my doctor just gave me what I said.