Jesus was very protective of Mary because He understood her heart. Throughout Scripture a woman is a symbol of the church, and flawed and defective though she may appear, Jesus is grieved and angered by those who, like Judas, stand by and accuse the bride of Christ. I know a fairly prosperous businessman whose son was convicted of murder and sentenced to life in prison. The loving father, convinced that his son was innocent, mortgaged his home and sold all of the family's assets in order to pay the legal fees to get his son another trial. Even though the conviction stood, the father never regretted the sacrifice.
Love gives sacrificially.
God the Father gave His all when He sent His only beloved Son. His lavish offering was in proportion to his great gratitude. Mary too felt compelled to give to Jesus because she appreciated how much she had been forgiven. Jesus looked at the woman, then back at Simon. You gave Me no kiss, but this woman has not ceased to kiss My feet since the time I came in.