They must have got divorced if he was planning to ask Tara to marry him.
He was very sad to see Sunita and their twins leave but let her go, thinking she'd calm down and they'd get back together. If I remember correctly, she left him when she discovered that he and Amber's mother lied to her about Dev being Amber's father plus Amber is not the only child he has that he hasn't had much, if any, contact with.