Smile though your heart is breaking is an old show biz commandment. This week no one knows the meaning of that commandment like Christina Aguilera, who performed in public on Sunday for the first time since her marriage breakup.

Aguilera, who announced her split from husband Jordan Bratman earlier this month, performed at The Justin Timberlake and Friends Concert in Las Vegas on Saturday with a little help from Elton John, Salt N Pepper, Selena Gomez and T-Pain.

Timberlake introduced the singer with serious praise as "no contest, the best vocalist of my generation,” and the blonde bombshell gave no trace of her heartache as she performed.

The former child star filed for divorce citing “irreconcilable differences” on October 14, however Bratman is reportedly refusing to leave their marital home.

Their marriage lasted five years and produced their two-year-old son Max, but Aguilera is finding the whole issue so painful she has been staying in a hotel since the split.

"It's not easy, and there have been a lot of tears and sadness," Aguilera told the press this week. "It's impossible to redefine yourself and your life overnight. Thankfully, I have my mom and a small group of close friends who are there for me 24/7 and whom I can trust and depend on.

"On days when it feels impossible to even get out of bed, much less function as a mother, their support and encouragement have kept me moving forward," she added.

Guinness-march2019