What does Butter-jug mean?

Butter-jug meaning in Urban Dictionary

A Butter-jug occurs when you put a stick of butter within the anus of lover. After that as soon as your lover has entered the career of standing on his or her mind, lean him/her slightly forwards. now wait for the butter in their rectum to melt and drip down their gooch and on your tongue.Note. The residue left out by the butter would make great rectal lube.