Usher and his longtime girlfriend Grace Miguel are reportedly engaged.

Sources close to the couple told US Weekly that the "OMG" singer popped the question with a gorgeous (and massive) diamond ring. Miguel was spotted rocking the stunning piece of jewelry while shopping in Miami, Fla. Check out pictures of the ring here.

"She's happy but they're trying to keep it quiet," the source told US.

Usher and Miguel have been dating since 2009, shortly after his split from ex-wife Tameka Foster. So far, the couple has not publicly confirmed the engagement rumors. In fact, Usher rarely talks about his relationship with Miguel but told Billboard in October that she's been there for him through some really rough times.

"I have an incredible partner and manager," the singer told Billboard magazine in October. "She has helped me through some the hardest times in my life and my career. She's someone who's been able to support and understand all of who I am. Not just as a dancer or as a performer or as a singer, but as a humanitarian and a business man and as a person."

Back in November, there were rumors that Usher was victim of an alleged sex tape. According to TMZ, Usher's car was broken into back in 2010 and the suspect took off with $1 million worth of jewelry, two cameras and two laptops.

Reportedly, on one of the laptops was a sex tape featuring Usher and Foster. At the time Vivid Entertainment and other adult film companies refused to touch the tape because they knew Usher would never agree to release it. The tape resurfaced in August but no one has bought it.