Kylian Mbappé acted as the elder brother figure, and after the official announcement of Ethan Mbappé's signing with Lille, the French international posted a heartfelt message on social media dedicated to his brother.

Ethan Mbappé signed his first professional contract with Lille after leaving PSG. This news delighted Kylian, who couldn't be prouder of his brother.

"Congratulations on your first professional contract. The beginning of a great adventure at a great club, all the best to you and your team," Kylian began writing in his post.

At 17 years old, Ethan has already had his first minutes in elite football with PSG, but now he faces the challenge of making a name for himself in the sport. Kylian will be there to support him.

"I'm your number one fan. The toughest part is just beginning but you'll achieve it," encouraged the Real Madrid player.

Next season, they won't be as close to each other, but Kylian made it clear that won't be an obstacle to seeing each other. "Looking at Madrid-Lille flights now," he humorously concluded.