It’s thought Brit’s beau of three years surprised the pop princess with a Neil Lane sparkler last Thursday, during an evening out to celebrate their 30th and 40th birthdays.
'OMG. Last night Jason surprised me with the one gift I've been waiting for. Can't wait to show you! SO SO SO excited!!!! Xxo' Brit gushed to fans on Twitter during the night.
And the couple wasted no time in celebrating, jetting to straight to Vegas to after confirming their happy news.
'Still glowing! About to jump on a plane to Planet Hollywood in Vegas,' delighted Britney revealed.
Dressed in a figure-hugging banding dress, Brit flashed her diamond dazzler for the very first time as she arrived at the event.
Speaking to American magazine People, celebrity jeweller and the ring's creator Neil Lane revealed: 'Jason is a romantic and when I asked him to tell me about Britney and what the ring would represent to them so I could find inspiration, his response was always the same — she is his princess!'
Set in platinum, Brit's dazzling ring features a huge sparker that 'looks like a mini crown,' as well 90 small diamonds around the band.
After dancing the night away during her evening of celebration, Brit Tweeted: 'Tonight was one of the most magical nights of my life. Such an amazing time with my new fiancé and our closest friends and family. #Blessed'
Congrats to the happy couple!