The product derived from the act of using a crotch as the churn, and a penis as the plunger. Most successful after several sessions, when there is enough accumulated fluid (both penile and vaginal 'milk') to facilitate the churn action.
Commonly noticed among milk fetishists, the addition of real milk (for best results use whole milk) or cream speeds the process.
Churning the cream brings its fat globules together and causes them to clump into lumps of crotchbutter, leaving a liquid called crotch milk.
Generally an acquired taste, as it is a bit tangier than the common grocery store variety. However, some people actually enjoy the taste of properly churned crotchbutter the first time.
Also possible to make chocolate crotchbutter, and chocolate crotchmilk by repeating the process in the anus. Only the truly hardcore appreciate the taste of this 'delicacy'.
After several hours of creampie sessions with Samantha, Joey noticed the crotchbutter had achieved the perfect consistency for consumption. As he went down to sample the delectable delight, he exclaimed, "Holy shit girl, this crotchbutter is the bomb!"