Mbappe had a very public spat with his manager Thomas Tuchel after he was substituted on Sunday night.
As he left the pitch, he ignored the German coach's words and was actively trying to move away from him.
It was widely reported that this could spell bad news for Tuchel as PSG boss, but it may rather be indicative of Mbappe's own discontent.
According to Spanish sports radio station Cadena SER, Mbappe has refused to sign a new PSG deal because he wants to sign for Real Madrid.
It's understood that Mbappe and his family have always hoped to end up in Madrid.
Both Zinedine Zidane and Florentino Perez were reportedly made clear this was the case in May of this year.
The 20-year-old still has a contract at PSG until 2021, but the club have made improved offers to try and convince him to stay.
It's reported that their latest offer was for €26 million per year, which is double what Mbappe currently receives.
The Qatari owned club are thought to be willing to go up to €36m per year and thus equal Neymar's current deal.
PSG reportedly want Mbappe to be their poster boy and have told him that's the case, but he is not willing to listen.
This could spell the beginning of the end of Mabppe's time in Paris and Real Madrid are believed to be making preparations for a bid in the not-too-distant future.
The Frenchman has 12 goals and five assists in just 15 games in all competitions so far this season.
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