What happened to Luv and Kush after Ram and Sita?

What happened to Luv and Kush after Ram and Sita? Kusha was the eldest son and he was appointed as King of Kushavati. Kusha was the one who rehabilitated Ayodhya and made it regain its former glory. His successor was named Atithi and from Kusha the Raghukula continued its reigning line of kings. Kusha was married to Naga Princess Kumudvati, sister of Naga King Kumud. He raised her to the rank of Chief Queen. Kusha got a son from her Atithi who was very skilled and intelligent young man and was jewel of both dynasties (Raghu and Naga). He was crowned as Prince Regent when Kusha left to fight a giant. Kusha killed the giant but got fatally injured. After his death, Kumudvati followed him and they reached heaven where Kusha shared throne of Indra and Kumudvati shared with Indrani (Sachi). Another name Champika is mentioned as wife of Kusha in Ananda Ramayana. Luv was appointed King of Shravasti. He also built Lavapuri (Lahore). His wife is called Sumati in Ananda Ramayana. Sources- Ananda Ramayana, Valmiki Ramayana and Raghuvansh by Kalidas