Angels are different than humans, they made their choice once and for all. Humans choose and re-choose throughout their lives, we do thinks we kind of want to do but don't really want to do (think getting in an angry argument and saying things you regret) in part because our emotions get the best of us. Angels and fallen angels are spirit, they don't have hormones or things like that and their knowledge is of a higher degree and their will is stronger. So angels made a deliberate, knowing, decision for or against God and that decision is final.