The two players are the hottest couple in French football. Ever since the capital's team signed the former Barcelona player, breaking more than one economic record to bring him from Spain, they have become inseparable both on and off the pitch.
That's why there's so much debate about who's better, who's the club's favourite or what would happen if they split up. In the meantime, they continue to do their thing by giving great performances on the pitch, although the French striker has had more continuity lately.
He spoke all about it in an interview to 'France Football': "When I arrived, there was no debate. He was the superstar. He lost the World Cup and I won it: people started saying things about our supposed rivalry. I was shocked to read all that, so when he came back from holiday, I went to see him."
He continued: "I told him: 'You didn't do well in the World Cup... and that's better for us. Don't worry here, I'm not going to steal your place. I'm going for the Ballon D'Or because you can't win it this year, but I assure you I don't want to take your place: you can keep it. I'm here to help you."
He also spoke about the battle with Messi for the Ballon D'Or: "I wanted to go for that trophy, but there was Messi. I scored two, he scored three, I scored three, he scored four... It was so incredible that I talked to Ousmane (Dembélé) about it: "It can't be: does he do it on purpose or what? Is he looking at the goals I score?"
His countryman's response was clear: "Of course he does. "I thought: 'Messi's watching me... It's flattering to have a player like him watching you." Dembélé's tip-off makes it clear that the Argentinian is keeping a close eye on his competitors.
Mbappé also spoke about the Olympic Games: "Of course I want to go, but I don't control everything. If the club, which is my employer, doesn't want me to go, I won't confront them. We will soon talk to Leo" (Leonardo is the sports director of PSG).