That love is an infinite series of trade-offs between painful and rewarding events is amply brought out in this film. Lesbian lovers are drawn together in a give-and-take relationship. One gives pain, while the other so eagerly accepts the pain with a smile.
The dominant one lavishes spankings upon the submissive partner who endures that pain with love and affection. These young ladies thus have found a common thread on which to build a healthy dom/sub relationship. Enjoy!