An anal saliva produced after a firm stool. Sometimes moist, sometimes crusty, residual soaked in anal hair as a result of leftover nuggets from last weeks dinner. Advisable to be trapped between ones forefinger and thumb before bedtime. Cleansing of the hands is a nicety, but by no means necessary to create finger butter the next morning. Otherwise a blowback to 70s butter. Bastardised use of the term rectum butter. Back in the day was called a 'kling on'. TUCKERS TIP: No matter how dry ones toast is, never use in place of cow butter. Best removed by foreplay. sometimes called ass junipers
Mummy mummy, my toast is dry, do you have any of that recto butter daddy always talks about?
No son, if your too young to produce your own, get some cow butter.