Donald Davidson's idea of a Primary Reason can be summed as a reason causes an action. The prototypical example is you want light so you turn a light on. And sure it can be pared down to multiple reasons, such as being afraid of the dark or staying in a place that you can't navigate in the dark. But even then, Occam-wise you turn the light on because you want light.
Kant believed that for a thing to be moral (action), one must not benefit from it because that destroys its value. Giving a beggar money then is not moral because one could benefit from it because one feels better about one's own condition. Basically altruism does not exist, as argued earlier (http://thewhyquestion.blogspot.com/2011/03/altruism-aka-lie-we-tell-ourselves.html).
Love is defined as having affection and personal attachment for something. We can love bacon (reason) so we cook and eat it as often as possible (action). But we benefit from it because it fulfills our need to satiate our need to eat the bacon.
So how does this apply to what is considered a love between two persons?
Let's assume that love between two humans follows the standard definition. Person 1 and 2 love each other because each provides affection and a feeling of personal attachment for the other. They can be considered "in love". Love then is the action.
From the Davidsonian standpoint, what are the reasons for love? If we desire affection and personal attachment, then love is a Davidsonian "thing". What we do gets us what we want. There is no Existential angst involved.
But as far as Kant's morality goes, if we desire love and affection, love is not moral because we benefit from it. Our reasons cause an action that gives us what we desire and is therefore immoral. We must love without expectation of any kind to satisfy Kant.
And that brings us back to Davidson. Can we love without any expectations?
There are no instances of love that do not invoke actions. We can not love for the sake of love because even then the action of love is caused by the action of loving. And because we benefit from this it is not Kantian moral.
The conclusion then is that love is both Davidsonian and Kantian. Love is not moral and benefits us. Love is never altruistic and always beneficial. Love is simply something that benefits us.