eat cheese and crawl up my ass
A phrase so bad it makes the other person want to take a nap, eat a donut, and forget the whole thing ever happened.
I said it to my mom after she yelled at me for getting a C on my math test.
My dad said it to me when I told him I was joining the band and not the football team.
My friend said it to me when I told him he was the worst at hide and seek.