CHRISTINA AGUILERA ENGAGED AND PREGNANT WITH SECOND CHILD

Oooh Baby! There will be more little voices in the house these days because, 33 year old Christina Aguilera knows how to keep things interesting -- it hasn't even been a week since she announced her engagement to a production assistant ... and now she's pregnant.

Christina and soon-to-be baby daddy/husband Matt Rutler met on the set of the 2010 film "Burlesque," where he worked as a P.A. And things heated up from there.

Aguilera announced they were engaged on Valentine's Day. Christina gave birth to her first child -- Max Bratman -- in 2008.

Pretty crazy timing ... Aguilera lost a ton of weight just last year. Aguilera,  has enjoyed watching her now-6-year-old grow. The "Beautiful" singer took season 4 off from The Voice to spend more time with her family and to focus on her music career. 

She's also taking off season 6 of the show, when Shakira will fill the pop diva's red chair.

The newly-engaged couple and expectant parents have been together for almost three years. They met on the set of Aguilera's 2010 film Burlesque. The seasoned vocalist was previously married to Jordan Bratman. from November 2005 to October 2010, and he shares custody of Max.