Why didn't Ronaldo celebrate his goal?

Cristiano Ronaldo seems to have popularised the new trend of not celebrating goals.

The Real Madrid talisman did it again at Old Trafford on Tuesday night.

Ronaldo slid the ball into the net at the far post off a pass from Gonzalo Higuain and thus nailed the victory for Real.

But what could have been a natural reaction to celebrate, Ronaldo shrugged his shoulders and reacted as if apologising to the fans.

But didn't the Portuguese forward move to Real Madrid for a record sum of 80 million pounds (about Rs 662 crore)! And time and again he mentioned that it was his dream to play for Real Madrid. Why so much drama, then?

Also what happens to the sentiments of the fans of his current club?

One fails to understand where does Ronaldo's loyalty lie?