Remember the show How I Met Your Mother? Well, Cristiano Ronaldo does not want to tell that story to anyone- not even to his son.

Ronaldo has a four year old son named Cristiano Jr., and he still has no idea who is mother is since his birth in 2010. Nevertheless, the poor child could not do anything about it, as he reportedly stopped asking about his mum at this point.

The Portugal superstar was believed to have a child with an unknown woman who was imagined to be a surrogate.

The Real Madrid star's sister Elma said:

"Once we told him she was in Heaven, but my brother and mum asked us not to repeat it.

"We say now his mum went travelling. He goes silent, forgets about it. He doesn't ask anymore."

The four- year- old son was nicknamed as Cristianinho. He currently lives with Ronaldo and Ronaldo's mom, Dolores, in Spain. The forward's mom recently published an official biography that gives some clues on who the mother is.

Nevertheless, Cristiano Sr. says, 'The mom will never be known.'

However, his sister also added: 'If later on Cristianinho wants to know who his biological mum is, it will be his decision and no one's going to stop it.'

It seems as if the family have really never talked about the mystery woman, as they do not even have one story to say to the superstar's toddler.

Nevertheless, Cristiano Ronaldo is currently dating supermodel Irinia Shayk. He said: "Dolores knows sooner or later he'll get married."

Cristianinho is always appearing in his father's social media posts in Twitter and Instagram.

Ronaldo recently also just said that he is now fully recovered from the injury he is suffering from in the previously concluded World Cup. He will now play for Real Madrid in the upcoming Premiere League.

With reports from: dailymail.co.uk/ mirror.co.uk