Tolong jelaskan mengenai Leksikon dari Lurah punggung dalam bahasa melayu

The terms plumber's crack (Canadian, Australian and American English), and builder's bum (British English) refer to the exposure of male buttock cleavage, especially on occasions of careless bending over. The expression "builder's bum" was first recorded in 1988. The terms are based on the popular impression that these professions are particularly prone to this kind of mishap.