It’s only been about three months since Christina Aguilera gave birth to her second child, daughter Summer Rain. However, the pop singer stepped out on Sunday night and revealed a smoking hot post-baby body.

Aguilera and fiancé Matthew Rutler attended the Breakthrough Prize Awards at Hangar One in Mountain View California last night. Aguilera wore a fitted red full length gown with plunging neckline that showed off her slim figure and sexy curves.

The Genie in a Bottle singer has clearly been toning her physique since giving birth in August. Sources told Us Weekly that Aguilera has put a lot of work into getting back her slim figure, “Christina has hired a trainer and is really dedicated to getting thin again,” one source reported to Us. “She lost 46 pounds from changing her diet and working with a personal chef,” added a different source.

#ChristinaAguilera steps out and looks the flyest she's looked in quite some time. http://t.co/IEGxf274it pic.twitter.com/ITVy16krbv

— Yahoo Celebrity (@YahooCelebrity) November 10, 2014

The pop icon hit the stage on Sunday night to perform her moving 2002 hit Beautiful. The NASA sponsored event honors achievements of Breakthrough Prize Scientists.

Aguilera was in the news this past July when she posed nude for V magazine. The singer was not shy in showing off her baby bump. She explained, “As a woman, I’m proud to embrace my body through all stages of life, staying fearless and confident in surrendering to the unknowns the future has in store.”

It was also confirmed in October that Aguilera would be returning for Season 8 of the hit reality show singing competition The Voice. She will rejoin coaches Adam Levine and Blake Shelton, plus singer/producer Pharrell Williams. Gwen Stefani will not be returning for another season. Season 8 is set to launch this Spring.