He loves her and doesn't mind a sibling relationship.
She loves him, but it is a hopeless love.
Some love is destined to be fruitless. Those who fly to the flames are as heroic as dying, just because they are unwilling to do so.
I love you, this love has nothing to do with identity, status or age.
If I can be with you, even if all my sins are deepened, it doesn't matter.