Sunny days are over for Cristiano Ronaldo and Manchester United.A one-of-a-kind fairytale of a long lost son who returns home after years of exile has somehow turned into one of those excruciating family traumas.After less than six months at Old Trafford, the Portuguese superstar is starting to show his dissatisfaction, to put it politely.’Why me?!’ Ronaldo didn’t hesistate to show his anger (©Marc Atkins/Getty Images)It exploded on Wednesday night, as United interim boss Ralf Rangnick decided to replace Ronaldo with 19 minutes left in a tie against Brentford. CR7 lost the plot instantly, demonstrating anger management issues, as he acted like an immature child whose favourite toy had just been taken away from him. Later in the post-match press conference, Rangnick explained: “The only reaction I got was, ‘why me? Why did you take me off?’ I had to take the decision in the interest of the team and the club. We did the same thing when 2-0 up at Villa and didn’t want to make the same mistake again.”United’s win: Forgotten strikers finally on target, Ronaldo still made the headlinesHowever, there’s much more to worry about at Old Trafford than Cristiano’s childish behaviour in the dugout. Because, obviously, his second tenure at home is not what he expected it to be.According to Sky Sports, he has apparently told Manchester United he will leave this summer if they do not qualify for the Champions League.Keane: “Ronaldo has not come back to Man United to sit on the bench”; Carragher: “I don’t think it should be a big story if Ronaldo doesn’t start every game”Other British media report Ronaldo informed new CEO Richard Arnold of the ultimatum last week.There’s no such thing as a fairytale in modern football. It’s about time we acknowledge that.THU: 22.45: (3.35) ARSENAL (3.45) LIVERPOOL (2.15)