When someone is saying something that is either annoying, complicated, not believable or you simply don't know what else to say, you just ask them what they're yapping about.
Person K: bro i just clap some account 200dl rn stfu nahh bro
Person B: what are you yapping about
Used by mostly middle schoolers, primarily ones who have fallen victim to the "sigma" male, Andrew Tate, and Ohio trends as a counter-argument for someone promoting an opposing topic. (i.e. LGBT rights, Atheism etc.)
It is commonly used as a last resort whenever these people run out of valid arguments.
WE ATE YOU UP PERIOD
what are you yapping about