Indra dev was insecure about his throne of heaven because of Kartikeya. He thought that Kartikeya is the son of Mahadev and He can offer him the throne anytime He wish to.
When Shiva ordered Kartikeya to go south and protect the people there from demons, Indra sent one of his nymph, devsena, to disturb and deflect Kartikeya from his mission by luring him.
Devsena made a story and started living in the kingdom where Kartikeya stayed. Soon she started loving him in real.
Devsena told Kartikeya about her feelings and he respected it. But as soon as she informed him about Indra, he got furious and refused to marry her.
Later, Indra himself requested Kartikeya to marry Devsena. Then Brahma dev appeared and informed everybody that Devsena was his Manas (Psychic) daughter. Due to some Karmas and deeds, she turned into a nymph.
Kartikeya married Devsena. He is also married to Goddess Valli.
Because of the elephant face of Ganesha, no girl was ready to marry Him. In anger, he ordered his mouses to dig the roads from where any deity would pass with procession.
Troubled deities went to Brahma dev for the solution. To calm Ganesha down, Brahma dev created two girls Riddhi and Siddhi. They married Him and gave birth to Kshem and Laabh.
Nandi’s Father Shilad was tensed because Nandi wasn’t ready to marry. Mahadev assured Shilad that he will convince him. Mahadev asked Varun dev to marry her daughter, Suyeksha, with Nandi. He delightfully agreed.
Nandi wasn’t ready to marry because he wanted to serve Mahadev independently and without any hindrance.
Mahadev enlightened him about the importance of marriage and how it completes the life of two human beings. Listening the ken of marriage, Nandi got ready to marry Suyeksha.
Shilad, Varun dev and Shiva organized a ceremony where Nandi married Suyeksha.