Suck your dad's dick on the Moon
To care so little about someone's opinion that you are willing to expend an extreme amount of effort to show how little their opinion matters to you
"You think I give a shit what he thinks? I'll suck your dad's dick on the Moon!"
"As if it weren't clear enough how little James thought of his critics, he proceeded to suck their dad's dicks on the Moon."
"As if it weren't clear enough how little James thought of his critics, he proceeded to suck their dad's dicks on the Moon."