When Vishnu transformed into Mohini, the celestial enchantress, Shiva was so overwhelmed with desire that he abandoned his consort Parvati and ran after Mohini until he had shed his seed.
link: https://en.wikiquote.org/wiki/Mohini#Seven_secrets_of_Vishnu
In the Brahmanda Purana when the wandering sage Narada tells Shiva about Vishnu's Mohini form that deluded the demons, Shiva dismisses him. Shiva and his wife Parvati go to Vishnu's home. Shiva asks him to take on the Mohini form again so he can see the actual transformation for himself. Vishnu smiles, again meditates on the Goddess, and in place of Vishnu stands the gorgeous Mohini. Overcome by lust, Shiva chases Mohini as Parvati hangs her head in shame and envy. Shiva grabs Mohini's hand and embraces her, but Mohini frees herself and runs further. Finally, Shiva grabs her and their "violent coupling" leads to discharge of Shiva's seed which falls "short of its goal," suggesting the act was not consummated. The seed falls on the ground and the god Maha-Shasta ("The Great Chastiser") is born. Mohini disappears, while Shiva returns home with Parvati
link:https://en.wikipedia.org/wiki/Mohini#cite_ref-Vanita69_29-0
Why and how did Lord Shiva, the supreme yogi, fall in love with Mohini? Any Shiva bhakt will be shocked if they read about this! Also, he is already married to Parvati, who is Tripura Sundari, the most beautiful woman in the three worlds? Finally, I am aware of answers that state that this union was for the birth of Ayyappa or that this happened because Lord Vishnu is supreme and whatnot. However, I am searching for a different answers. Please give me your answers.