I realize I may be asking the unanswerable, but I'll take a shot.

Daniel Tudor's Korea: The Impossible Country lists this fascinating tidbit in the chapter on homosexuality:

King Sejong the Great himself was advised by ministers to disown his daughter-in-law for the crime of having sexual relations with maidservants. This case has the rare distinction of being recorded in royal documents. We can probably infer that the scarcity of such tales in official records is more of a result of the aversion and taboo that had by then developed than an indication of the absence of homosexual practices.

I started researching to figure out more about this lesbian consort. Initially finding this on Wikipedia, clearly written by someone less than versed in English:

After Royal Noble Consort Hwi of the Andong Kim clan lost her position, Royal Noble Consort Sun of the Ha-eum Bong clan (순빈 봉씨) became crowned prince's second wife. However, she was so lonely that she loved one of the made [sic] named So-ssang (소쌍). Also she relied on alcohol too much and at that time period, woman drinking too much alcohol was unacceptable. She lost her position because the king found out that she was a lesbian.

A little bit more and I found this article which focuses on Munjong's marriages (prior to becoming King). The relevant portion below:

Prince Munjong second wife's surname was Pong.'' But the situation did not improve on the front of bearing sons for the royal family, a serious problem for Munjong's father, King Sejong. King Sejong hoped his son would have a boy baby who could continue the throne, but the night affairs between Munjong and his new wife were not fruitful. To resolve the issue, King Sejong brought in three young ladies to put a spin on the troubled marriage life of Munjong. King Sejong's intervention no doubt displeased Pong, but there was nothing she could do except suppress her overwhelming anxiety and jealousy. Unfortunately, one of the three ladies, Kwon Sung-hui, got pregnant after a nightly visit by Munjong. Desperate to secure her position, Pong spread false rumors including a lie that she herself was pregnant. The false news reached unsuspecting court officials and King Sejong. Filled with joy, King Sejong even asked his daughter-in-law to move into an inner court room to keep her from any possible harm. One month later, Pong said she suffered a miscarriage, in her continuing effort to hoodwink the king and others. Pong's weird acts went out of control in the wake of the mock pregnancy scandal. She was caught looking through the cracks of a restroom wall to peak at men outside of the palace. In addition, she forced her servants to sing songs about love affairs. Even more shocking was that Pong was believed to be a lesbian.'' According to the Annals articles, Pong loved her female servant named So-ssang.'' Since Pong showed a particularly strong affection, So-ssang was deeply troubled. So-ssang later testified that she was forced to sleep with Pong. Last year, Crown Princess called me and asked me to stay at her room that night. I declined, but she screamed so much so that I obliged. When I was half- naked and entered the room, she took away my clothes and forced me to assume a position as if having sex with a man,'' So-ssang said. When King Sejong called Pong to ask her about the incident, she gave a different story. Pong argued that So-ssang was in love with another servant girl and that she had never slept with So-ssang. But, the truth finally came out, and Pong was expelled from the palace, her royal title canceled.

The website gives a strong impression that this comes from the Sillok Royal Annals, so I hope I'm not barking up the wrong tree if I ask if this is what the Annals recorded?

And otherwise, what happened to Bong Sun? She was stripped of her Royal title, but what did that mean for early Joseon? Was she a commoner? Was she still a noble lady? Would she have returned home to her clan to be married off to a less prestigious husband? Would she suddenly be an outcast, on the level of Gisaeng and bandits?