Parental love is unconditional love,
You see I disagree that parental love in unconditional.
It could be argued that parental love is predisposed by genetic programming, that it's just an evolutionary process in action.
You could argue that real love is one whereby you have nothing to gain on any level. Romantic love certainly doesn't count in that respect and neither would parental love.
When you send money to a hungry stranger, is that unconditional? In a way not really, because even then you have something to gain - a feeling of wellbeing.
So doesn't all love have some kind of condition attached to it, at least for us as humans? Perhaps there's a species somewhere in the universe that has trully unconditional love.
Perhaps it's doing your duty, as Kant described. Perhaps that is love.