This was originally done as a gift for forgemaiar on tumblr.
It had been a source of great confusion to Ulmo once, how everyone apologized or lamented his lack of a spouse. It was as though they felt he lacked something because he did not have the great loves that existed between Manwë and Varda or between Namo and Vairë.
He preferred to liken himself more to Aulë who’s love for his children and those under his care was never lacking or Yavanna who loved to care for all even though the two of them shared a great love. Their love for those who remained in their sphere of influence resonated in him, and he found himself glad to hear of how their little ones Mitsanár, and Mairon were doing though he more often spoke of the two himself. Still he never felt a lack.
He did have Ossë and Uinen along with those who were theirs. All of whom he loved dearly and missed when they were away for any reason. He made it a point to welcome them and all of their children into his home the seas and whenever he found little Ulodin wandering lost or alone well he was happy to give her all of his free time to teach her more about the deeps same as any of the other children of the Maiar in his domain.
So no he had no great love. It was not something he needed. After all if he had that he may have missed what he did have.