one in the pipe
The act of farting and producing a noxious odour, due to needing the bathroom immanently - there is one in your 'pipe'.
Dave let rip and his drinking buddies guffawed and covered their noses.
"One in the pipe, old son?" Inquired Pete with a wink.
"One in the pipe, old son?" Inquired Pete with a wink.
one way pipe cleaner
Refers to urination or ejaculation, which clears the urethra.
Guy: I just took a one way pipe cleaner to relax a bit.