Kelly Clarkson gave Demi Lovato a special birthday treat as she sang “Cool for the Summer” during Wednesday’s Los Angeles concert at the Staples center.

According to E! News, the “Heartbreak Song” crooner told the audience about Lovato’s birthday and that she wanted to sing the former Disney star’s new single as a special birthday gift. "It's one of my girl's birthdays tomorrow ... and when I say my 'girl,' I mean Demi Lovato. She's always been so supportive and so cool ... I thought I would, for her birthday, sing her new single," Clarkson said.

After the concert, Lovato found out about Clarkson’s birthday gift and took to Twitter to thank her fellow singer. She wrote: "WOW WOW WOW.. @kelly_clarkson thank you SO MUCH for covering #coolforthesummer at your show tonight!!! BEST BDAY GIFT EVER!! *literal tears*." 

Meanwhile, aside from doing a cover of “Cool for the Summer,” Clarkson also announced about her pregnancy. The "American Idol" winner admitted that it wasn’t the way she wanted to announce her pregnancy and even apologized to her husband, Brandon Blackstone. She added: “This was not planned. I'm just so hormonal. Everything is great, I haven't vomited yet. That's a win y'all."

However, earlier this year, the singer and songwriter told People magazine that she was nervous about having a second child. Clarkson mentioned that she was “frightened to have another one” since her first child, River Rose, was “so perfect.”  Her daughter was reportedly a very good sleeper and a very happy baby. Clarkson joked: “I feel like something horrible’s gonna come out of me. Because she’s so great — like, the yin to her yang. But I won’t put that out there.  I’m gonna project happiness.” On having another baby, Clarkson said she wanted to have one “in a couple of years.”

Well, it looks like the “Stronger” singer would need to make room for baby No. 2 much sooner than she expected. 

Clarkson and husband Blackstone tied the knot in 2013 and are parents to 1-year-old daughter River Rose.