One of the Pharisees asked Jesus to eat with him, and he went into the Pharisee's house, and took his place at table. And behold, a woman of the city, who was a sinner, when she learned that he was at table in the Pharisee's house, brought an alabaster flask of ointment, and standing behind him at his feet, weeping, she began to wet his feet with her tears, and wiped them with the hair of her head, and kissed his feet, and anointed them with the ointment. Now when the Pharisee who had invited him saw it, he said to himself, "If this man were a prophet, he would have known who and what sort of woman this is who is touching him, for she is a sinner." Luke 7:36–39 (RSV)
There are at least two sinners in need of God's mercy in the Pharisee's house. The woman had no illusions about who she is. St. Luke introduces her as a 'woman of the city,' a polite way of naming her profession. In case his readers might be uncertain, St. Luke adds, 'who was a sinner.'
It is unlikely that she lacked help remembering her sin. Whispered conversations as she went about the village. Disapproving looks should she dare to pause too long in the presence of 'respectable folk.' A confrontation by a synagogue leader or Pharisee about her life was not uncommon.
She probably did not ask anyone's permission to enter the Pharisee's house. She wanted to be a Jesus' feet, to weep over her broken life and hope for some shred of mercy.
The Pharisee, if he thought about his sin at all, would have rated it on a sliding scale. His minor failures on one end, the woman's terrible transgressions on the other. Instead of seeing that he should join the woman weeping at Jesus' feet, his estimation of Jesus fell.
The woman and the Pharisee needed Jesus, for they were both enslaved to their sins. She saw it. He could not. The Pharisee had fallen into the snare of the devil, where religion is used to beat down sinners. Instead of seeing hope for the woman in Jesus, the Pharisee only could wrongly judge them.
The Pharisee was more lost to the Father than the woman. She could only weep at Jesus' feet. He trusted in his goodness by comparison. The Father blesses a sinner's tears.