The Swallow and the Happy Prince have a relationship of Platonic love. Platonic love is non-romantic, non-sexual love between two parties that share a close emotional and spiritual bond.
Initially, the Swallow is attracted to the Happy Prince for practical and superficial reasons. Seeking a place to rest on his journey, the bird alights at the foot of the statue of the Happy Prince and delightfully declares it a “golden bedroom.” When the Swallow sees the crying prince’s visage, he thinks that the prince’s “face was so beautiful in the moonlight that the little Swallow was filled with pity.” This is the first inkling of the Swallow’s growing emotional bond with the prince. The bird also notes—a bit snobbishly—that the prince is not made of solid gold; nonetheless, the bird does not want to hurt the prince’s feelings and politely does not say anything.
The relationship between the Swallow and the Happy Prince deepens through shared emotion. Although initially the bird does not plan to stay with the prince, he becomes moved by the prince’s story and heartache over a sick boy: “the Happy Prince looked so sad that the little Swallow was sorry.” Over the course of three nights, the prince appeals to bird’s emotions and convinces the bird to take the statue’s jewels to help a sick boy, a cold and starving playwright, and an abused poor match girl.
The Swallow becomes loyal to the Happy Prince because he grows to love the prince. Feeling “warm” from helping others, the bird discovers compassion for others; he learns sympathy and empathy from the prince. Admiring the prince for his selfless gifts to others, the Swallow develops his own spirit of generosity and tells him,
I must leave you, but I will never forget you, and next spring I will bring you back two beautiful jewels in place of those you have given away.
The Swallow and the Happy Prince share a spiritual bond of compassion for others; this shared bond becomes the backbone of their Platonic love relationship. The Swallow demonstrates ultimate loyalty to the Happy Prince when the prince commands the bird to take one of the his jewels that represents an eye. The bird weeps not for the superficial reason of a lost jewel but for the fact that the prince willingly sacrifices his eyesight to help another person. Nonetheless, the Swallow supports the prince's wishes. After the prince goes blind in order to give his last jewel to a match girl, the Swallow vows to stay with him always. The bird continues the prince’s mission of alleviating the townspeople’s misery by stripping the statue’s gold leaves and delivering them to the poor.
The poor little Swallow grew colder and colder, but he would not leave the Prince, he loved him too well.
In the end, the Swallow dies at the Happy Prince's feet; ultimately, both the Swallow and the Happy Prince are joined after death as Platonic lovers.