The one thing Costa does that is basically better than every single other player, is he does this crap behind the ref's back like no other player manages. His absolutely disgusting spitting into his hand behind the ref, then throwing it up in Ramos/Pepe(forget which) face to hide spitting in a players face was truly unbelievable. Surprised Ramos hasn't hurt him in training.
He managed to have a half sensible season leading up to both a big move/world cup year, probably not a coincidence, the season before that he was an utter disgrace on the pitch.