Perhaps represents「two dog lances in erotic orifice(s)」of a service provider simultaneously.
「Orifice in skin fold of no-longer-integrated foot that is narrow and tiny causing many repeated attempts at entry」describes a situation in which normally the participants would call it quits, but must continue due to the NEED TO FULFILL AN OBLIGATION, the personal commitment to FULFILL THE PERFORMANCE OF A PROMISE that was likely made by the household male to the shaman, or to the young girl at the time of foot-dis-integrating in order to console her somewhat, and now she has an artificial vagina in the sole of each foot that has healed sufficiently for first use…but, they are too narrow and tiny still for possible entry. Note the meanings of, TO ESTIMATE THE VALUE of something, to APPRAISE, and to RHYME as testing the results of each foot prior to the sale of the daughter as a slave:「In traditional Chinese medicine, there has never been a mental disease called pedophilia (or an equivalent term), or homosexuality, or most of the other so-called sexual variations for that matter. …Children are usually described as natural sexual beings and erotic stimulation and sex-play are seen as beneficial to their healthy development.」
[ https://docx2.com/wp-content/uploads/Are-Any-of-the-Pharaphilias-in-DSM-Mental-Disorders_.pdf 2023-05-14 ]
「Viewing women as commodities [see 品] was also made customary from Song Dynasty (960 - 1279) forward, both in the suddenly expanded labor market and within relationships. Men could sell their female kin to slavery or prostitution, and frequently did.」
[ https://www.zum.de/whkmla/sp/0910/hersheys/hersheys5.html 2011-04-05 ]
As a result, a variation of the standard practices must be considered, and perhaps the solution found was for the young girl to use her foot while standing over the prone male, TREADING upon his erection and sliding her foot forth and back to accomplish the goal, virtually STOMPING with all her tiny body weight to get it done:「Bound feet were a mark of beauty…[folks] took great pride in tiny feet, with the ideal length, called the 'Golden Lotus,' being about 7 cm (2.75 inches) long. …The process was started before the arch of the foot had a chance to develop fully, usually between the ages of 2 and 5. …Qing Dynasty sex manuals listed 48 different ways of playing with women's bound feet. …Bound feet rendered women dependent on their families, particularly their men, and became an alluring symbol of chastity and male ownership, since a woman was largely restricted…and could not venture far without an escort or the help of watchful servants.」
[ https://en.wikipedia.org/wiki/Foot_binding 2012-12-17 ]

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: to fulfill (a promise); to tread; to walk
Japanese EDRDG: step on, trample, practice, carry through
Unihan extended: trample, tread upon, walk on