Jennifer Lopez and Kim Kardashian are very close, claims Alex Rodriguez

Jennifer Lopez and Kim Kardashian West have been friends for a long time, however, Lopez's fiancé Alex Rodriguez has revealed that the two friends are very close and have a "beautiful relationship."

"We've all known each other for a long time. But Kim and Jennifer are very, very close," the Yankees legend told People. Rodriguez is co-stars with Jennifer Lopez and Kim Kardashian in the marketing campaign for Portal from Facebook, the smart video-calling system, with which he has partnered.

Rodriguez, nicknamed "A-Rod", further said that Kim is "almost like a mentee of Lopez, and the singer has mentored Kim a lot over the years," adding that "now they just go back and forth."

"They mentor each other and they have this really beautiful relationship that goes back over a decade and a half, and it's nice to do anything with Kim and our family," Rodriguez said.

In a commercial shot for the Portal video-calling system, the "Hustlers" actress is seen sharing a call with the reality TV star, both having their face masks on and ready for a "top secret" chat when Rodriguez enters the room wearing a matching mask of his own hoping to take part in the fun. "This is such fun. We should do this more often," he says in the advertisement.

The 44-year-old says he and his actress-singer fiancée have spent a lot of holidays with Kim, ranging from Taco Tuesdays at the Lopez-Rodriguez residence to Karaoke nights. Rodriguez further says that the "Keeping Up With The Kardashians" star is a "really good" singer.

Speaking about the video the three shot together for Facebook, Rodriguez said they have always found a way to stay connected even without the new devices.

"This is what we do, with or without this campaign. Now the fact that it is holiday season and now we're on opposite coasts and, of course, we want to connect to her, what better way to do it than with Portal for Facebook?" Rodriguez said.

"To see how much Kim and Jen like each other, respect each other, support each other is awesome," he added.