Green’s Dictionary of Slang

cut the crap v.

also cut the bull(shit), ...shit, cut one’s crap, cut out the crap, cut through the chicken fat, skip the crap
[cut v.4 (2)]
[1930s+] (US)

1. to stop wasting time or talking or doing something irrelevant.

2. attrib. use of sense 1.

3. as excl. cut the crap! don’t try to fool me! stop talking rubbish! etc.