Britney Spears raves about Madonna on her 64th birthday, posts photo of couple kissing

Britney Spears, 40, showed off her best "Vogue" performance in a new Instagram post on August 18, for Madonna's birthday. And in the same post, the "Stronger" singer shared an adorable snapshot that showed the two pop singers kissing at Britney's wedding. Of course, she also made sure to wish the singer a "Happy Belated Birthday," as Madonna turned 64 on August 16.

In the video portion of Britney's post, she is seen dancing to Madonna's hit song