Lady Gaga and her longtime boyfriend, actor Taylor Kinney, have become engaged, the singer said on social media on Monday.

"He gave me his heart on Valentine's Day, and I said YES!" Lady Gaga, 28, said on Instagram, displaying a photo of a heart-shaped ring.

The singer, who was born Stefani Germanotta, has been dating the 33-year-old Kinney for about four years, according to People magazine.

Lady Gaga, whose hits include Poker Face and Bad Romance, recently won a Grammy Award for her album Cheek to Cheek with veteran singer Tony Bennett.

Kinney stars in the NBC series Chicago Fire.