Wahahaha! Phil Collins use to walk around singing the song (before the drum hook kicks in), as if to build tension, and Fred nailed it in a humorous way!
Phil Collins has a great sense of humour. As he walked around the stage, at the farthest point away from the drum kit, people would start wondering if he could get there in time. He then turns around to the audience to say the line "don't worry!". Love it!