Complex sentence: What took place was that Marini was assisting the pope and was about to vest on him the mozzetta, Pope Francis simply said "I prefer not to", and there were no jokes about carnivals nor was Marini ever humiliated.
Split into simpler sentences: What took place was that Marini was assisting the pope and was about to vest on him the mozzetta, and Pope Francis simply said "I prefer not to". There were no jokes about carnivals nor was Marini ever humiliated.