let rip

phrase

: to say or do (something) without restraint

She let the ball rip. [=threw the ball very hard/fast]

… let rip at the airline in a series of insulting tweets …

—Julia Buckley

… couldn't help but let rip with the swear words …

—Julia Hunt and Bekka Barnard

… let rip with a wonderful long-range strike to deliver the winner.

—AAP Newsfeed

also : to remove limits or restraints from (someone or something) : to allow (someone or something) to act, function, etc. freely

… on the flat plains of Kansas I let the motor rip, even reaching 70 mph …

—David Tracy

… let his anger rip on Twitter when he failed to get any Grammy nomination love.

—idolator.com

But keeping rates low to save the banks will let inflation rip.

—David McWilliams

… the logic behind the movie is simple: Put Prince on stage and let him rip.

—polygon.com

… letting rip a huge fart …

—Elizabeth Aubrey

see also let it rip