If you had an employee who came back asking for a third raise in the last 5 months, after you've given him two already, what would you do?
You'd probably look at his production, what he costs, and what you'd replace him with and make the determination if he was worth the money. Or, maybe you'd simply say - I'm done with this bullshit. You aren't worth the headache. Ciao.
He doesn't need to stay, and he can do whatever he wants. Just like people can judge his actions towards a team that stuck by him, developed him, and paid him for his production. Nobody is required to wish him good luck.