Britney Spears' boyfriend thinks he is the "luckiest man on this planet".

Britney Spears

Britney Spears

The 'Toxic' hitmaker has been dating Sam Asghari since they met last year on the set of her music video for 'Slumber Party' and the hunky model paid a touching tribute to the singer - who has sons Sean Preston, 12, and Jayden, 11, with ex-husband Kevin Federline - on her 36th birthday on Saturday (02.12.17).

He shared a video of her blowing out the candles on her birthday cupcakes alongside a rose petal heart, and wrote on Instagram: "HAPPY BIRTHDAY TO MY ONE AND ONLY," he wrote. "Thank you for being you, thank you for showing me the true meaning of a beautiful woman and a strong mother, and most of all thank you for being mine. I consider myself the luckiest man on this planet @britneyspears #luckiestmanalive.(sic)"

Britney also received a birthday tribute from Madonna, who posted a video of herself covering her 'Me Against the Music' duet partner's classic song 'Toxic' before sending well-wishes for her special day.

Captioning the video, Madonna wrote: "Silence =Death! ... Song For World AIDS Day! ... #toxic #poisonparadise @britneyspears. Happy Birthday!! (sic)"

And in response, the 'Womanizer' hitmaker was motivated to share a video of herself covering Elvis Presley's 'Can't Help Falling in Love'.

She captioned her clip: "I was really inspired yesterday by @madonna's post. She's right... silence = death! These words really stuck with me, because they are so true.

"I've always wanted to do a performance like this... singing in a pretty little black dress, with a simple 360, one take shot! I figured since it was my birthday, why not go for it?! So boom When the clock struck 12:00, I did it!!!

"Thank you all for the beautiful birthday wishes, and for letting me do what I love. I appreciate you more than you will ever know!!!! (sic)"