“If this man were a prophet, he would know who and what sort of woman this is who is touching him, that she is a sinner.”
Yes, adultery and fornication are always gravely sinful, regardless of other circumstances surrounding these acts, and must be confessed before receiving communion. To break one commandment is to break them all. The sinful woman knew the gravity of her sins in the light of her love for the Lord. Only understanding His love enables the sinner to see the great evil of sin.
The Pharisee harbors a sinful judgment of the woman, that she makes Christ impure by touching him.
Her touch, however, is with sorrow for sin and love of God and results in absolution and grace.
Someone here needs to examine his conscience but it isn't the sinful woman: "her many sins have been forgiven because she has shown great love".
The Pharisee lacks the freedom to see himself with honesty, sinning in the very act of pointing out someone else's sin. The Lord then does for the Pharisee as Nathan did for King David: He acts for salvation and respects freedom. Salvation is a free gift. The self examination necessary for repentance is not authentic if it is not free, if it is forced, so the prophet tells a story and then asks a question. The response enables the guilty one to place himself in the story, and thus truthfully examine himself, leading to confession and forgiveness: "You are the man!"
The Lord gives you and me the same freedom, through the light of the Word, to also see ourselves with honesty, and then to receive the grace of sorrow for sin which prepares us to confess with sincerity and love.
When we touch Jesus in confession he makes us pure through absolution: “Your faith has saved you; go in peace.”