First a little protest... then a little pleasure.

After joining her fellow celebrities (and hundreds of thousands of others) at the Women's March in Los Angeles on Jan. 21, Demi Lovato headed to The Forum in nearby Englewood to cheer on new boyfriend Guilherme "Bomba" Vasconcelos in his welterweight match at the Bellator 170 event.

After the Brazilian athlete -- who's 6 feet tall and weighs 170 pounds, in case you were wondering -- defeated John Mercurio, the pop star posted an elated "HE WON!!!!!!!!!!!" clip on Snapchat.

A source told E! News that before his match, Demi, 24, was escorted to a ringside seat where she watched at least four fights before her man entered the ring.

She mingled with other MMA personalities, reports E!, and revealed to fighter Randy Couture and his girlfriend, actress Mindy Robinson, that she'd seen Bomba fight before but that this was her first time doing it as his girlfriend. "I'm freaking out!" E! reports she told the couple.

Backstage after it was over, Bomba headed straight for Demi. They kissed and shared a long embrace, the source told E!, and Demi repeatedly told Bomba, 30, "I'm so proud of you!"

Later that night, Bomba posted a pic of himself with the "Confident" singer, captioning it simply, " Happy 😍."

Happy 😍

A post shared by Guilherme "Bomba" Vasconcelos (@bombatuf) on

It's not the first photo of the two of them that he's put out there.

An hour earlier, he posted a snapshot of himself with Demi wearing a "Team Bomba" T-shirt and posing with a group of friends.

On Jan. 18, he posted a black-and-white photo of them embracing.

Demi was briefly linked to Bomba last summer following her June split from longtime love Wilmer Valderrama.

Last fall, she briefly dated another MMA fighter -- Luke Rockhold, 32 -- though was back with Bomba by late December, which the world learned after the two posed for a New Year's Eve snapshot together.