Is there any known case, where someone was sexually attracted to Buddha?
I recall there is a story (which is probably not from the Pali suttas but from a commentary) where a woman was in love with the Buddha so the Buddha used psychic power to make his appearance age before the woman, similar to the commentary story below:
Janapadakalyāṇī became a nun because her eldest brother (the Buddha) had renounced his kingdom to become a monk, his son Rāhula had become a monk, her own husband, Nanda, had become a monk, and her mother, had all gone forth. Due to her great beauty, she became known as Rūpanandā Therī. Hearing that the Buddha deprecated beauty, she avoided visiting him. However, hearing the lavish praise of the Buddha by the nuns and women devotees, she wished to see and hear the Buddha, so one day went with the other nuns, sitting behind them. The Buddha used his psychic powers to create a vision of a beautiful young woman fanning him. Rūpanandā was captivated by her beauty. The Buddha then caused the young woman to age gradually, slowly taking on the form of an old woman, then one dying in agony. Finally he made her body became a bloated corpse, pecked at by crows. Becoming thoroughly disgusted, Rūpanandā reflected that her own body was the same. Then the Buddha uttered the above verse and Rūpanandā gained Arahantship.
There was a monk named Vakkali who was attracted to buddha's physical appearance. He became a monk only to be able to stay closer to buddha and gaze at his beauty. Buddha warned him firmly by saying the following,
Vakkali, what is there in looking upon this filthy body? Vakkali, he who sees the Dharma sees me
and sent him away from his presence. Vakkali was depressed by this and wanted to commit suicide, however at the moment of committing suicide buddha was able to help him get enlightened. Source:http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2009/12/8.8-Vakkali-S-s22.87-piya1.pdf