Christina Aguilera Premiere’s Healthy Post-Baby Body While Spending Time With Ex And Son Max

New mom Christina Aguilera is keeping her body healthy and heart happy after baby number 2. The singer and her fiancé Matthew Rutler welcomed daughter Summer Rain into the world in August.

But the proud mother of two has more than just babies and fitness on the brain. She was recently spotted spending quality time with her ex-husband Jordan Bratman and their son Max.

Aguilera appeared to be enjoying herself with Max and his father Jordan, the songstress's ex. The parents seemed very friendly as they chatted at the school event in Santa Monica this week. In fact, the new mom appeared to seemed particularly radiant as she prepared for her little boy to go back to school.

So what's the "Beautiful" singer's secret? 

"Christina was very healthy throughout her pregnancy and is continuing it now after the baby," a source reportedly told E! News after the judge of "The Voice" was photographed for the first time with her post-baby body at 6-year-old Max's back-to-school picnic.

"She is very dedicated to yoga," added the source. "So much that she has never stopped practicing it. She did yoga the entire time she was pregnant. And Christina has already been working hard on getting her bod back in shape! She is doing private yoga sessions and loves how it makes her feel."

According to the insider, Aguilera "loves the way [yoga] makes her look and feel, inside and out. It's so calming and keeps her centered. She is obsessed!"

The pop diva has also been keeping her body healthy by "eating clean and watching her portions."

Weeks after Aguilera delivered new baby Summer Rain Rutler, the source affirms the mom is "all about family right now, that's what her priority is."

"Everything is about moderation," the source explains. "She will have cheat meals occasionally too. Running after Max also is helping her burn some extra calories. There's never a quiet moment, Max is very active!"

And big brother Max is on hand to assist with the baby girl.

"Max is being a very helpful big brother" and "loves having a little sister."