I suspect that Loki finally fell in with the chitauri and is, in fact, scared shitless of Thanos. So he basically stayed with them and did a lot of weedling until Thanos felt he had some entertainment value. He knew he was being used, that much is clear, what else can you do? He had no where to go and nothing else to strive for, except being King.

Hmm. TOP FIVE ICONS your favourite.