WBC/WBA welterweight champion Floyd Mayweather Jr.
WBC/WBA welterweight champion Floyd Mayweather Jr. sits in his corner between rounds during his title fight against Marcos Maidana of Argentina at the MGM Grand Garden Arena in Las Vegas, Nevada September 13, 2014. Reuters

Floyd Mayweather Jr. spoils his son like he has always done with his other children. The world's highest-paid athlete spent big bucks on his 15-year-old son by buying him a new Bentley as seen on his recent Instagram post.

"My son @kingkoraun wanted a Bentley golf cart for his 15th birthday so I made it appear," Mayweather wrote on Instagram on November 15. "Stay on the lookout for his gift for his 16th birthday."

As the highest-paid athlete, Mayweather sure has lots of money to burn. Although he is notorious for his frivolous spending, he also makes sure that he indulges his children in some luxury things or pleasure.

In May, the undefeated boxer reportedly paid singer-rapper Nicki Minaj $50,000 just to show up on his daughter Iyanna's 14th birthday party. According to a report by TMZ Sports, Minaj didn't really perform at the birthday party celebration. The "Anaconda" singer only stayed for an hour just to hang out with Iyanna and take selfies with the teenager. In 2012, Justin Bieber also graced Iyanna's birthday party. However, it is unlikely that Mayweather paid Bieber to come as the two shares a special bond.

Recently, Forbes Magazine has named Mayweather as the highest-paid athlete. Mayweather has earned $105 million. Although Mayweather didn't make big money from endorsements, in fact, he is the only athlete on the list to not earn income from sponsorship deals. He has made the vast majority of his money through his winnings.

Mayweather's fight against Canelo Alvarez in September 2013 has been recorded to have the highest-grossing pay-per-view revenue. The total revenue from his Canelo fight amounted to $200 million. In Mayweather's fight against Argentine Marcos Maidan in May has guaranteed him $32 million prize money.

The other athletes who made it into the top 10 of Forbes' 100 List of Highest-Paid Athletes include Cristiano Ronaldo ($82 million), LeBron James ($72.3 million), Lionel Messi ($64.7), Kobe Bryant ($61.5), Tiger Woods ($61.2), Roger Federer ($56.2), Phil Mickelson ($53.2), Rafael Nadal ($44.5), and Matt Ryan ($41.8).

Only two boxers have made it on Forbes' list. Mayweather's rival Manny Pacquiao is at the 11th place with $41.8 million earnings.