When you take something that works and absolutely fuck it up completely.

Named after President Joe Biden.
Guy 1; I did the engine rebuild on my motorbike last week and it was running brilliantly on two-stroke petrol and then Billy filled it up with four-stroke and blew the engine!

Guy 2; FFS, Billy is always Doing a Biden
by Bigg Benny August 27, 2021
Get a Doing a Biden mug for your daughter-in-law Sarah.
Fucking up something as fast as you can without regard to the outcome or peoples thought.
When Jeremy heard a rumor of being fired he started "Doing the Biden!"
by KSWILDMAN69 July 27, 2021
Get a Doing the Biden mug for your buddy José.