Kim Kardashian West has gushed over JLo's "hot" birthday outfit.

Jennifer Lopez

Jennifer Lopez

The 'Keeping Up With the Kardashians' star shared a photo of the 'On The Floor' singer, who celebrated her 46th birthday at New York's 1 OAK nightclub on Friday night (24.07.15).

Kim commented on her black sheer cutout dress, exposing her cleavage and used the hashtag "BodyGoals" and said she [JLo] will "forever be my idol".

Kim posted the image on Instagram, alongside a caption, which read: "Damn!!!!! How hot does @jlo look!!!!! She will forever be my idol!!!! #BodyGoals (sic) ."

Meanwhile, the star-studded bash had an unusual guest, in British star Natasha Bedingfield who was spotted on a boat before heading to the birthday celebrations at the popular NYC club.

The 33-year-old Brit shared also shared a picture with her new pal, JLo on her birthday. The 'Unwritten' hitmaker showed off her new pastel pink hairdo.

Sharing the photograph on the social media app, Natasha - who now lives in Los Angeles - referred to JLo as "darling".

The caption posted on Instagram read: "Happy birthday darling (sic)."