Lionel Richie has opened up about a rarely seen side of his late friend Michael Jackson.

In his debut memoir Truly, the 76-year-old All Night Long hitmaker revealed that the King of Pop was once nicknamed “Smelly” because of his unusual hygiene habits.

“His day-to-day life was what you could call eccentric,” Richie wrote. “Like an absent-minded professor but still a kid.”

According to Richie, music legend Quincy Jones would often jokingly tease Jackson. 

However, the pop star would laugh along, seemingly unaware that he sometimes went a couple of days without changing or washing his clothes.

Despite the quirky habit, Richie emphasized Jackson’s extraordinary lifestyle and constant creative grind played a role. 

“He was on tour performing in elaborate costumes made for him by his stylists, or he was in his pajama bottoms and slippers in the studio,” he added. 

“Or at home in something loose and comfortable so he could practice his dance moves and play with his menagerie of pets,” Richie recalled.

While Richie described Jackson as “very close with his siblings and his mom,” he noted that once the Thriller singer went solo and became the most famous entertainer in the world, “he was in charge of his own ship” quirks and all.

“Michael would laugh too, realizing that he was oblivious,” Richie added. “We all have our quirks.”