In her powerful performance, Gaga performed "Til It Happens to You," a song she dedicated to survivors of sexual assault.
During the song, 50 men and woman came out on stage with her, many of them with messages written on their arms in marker.
But now, they all share something that can't be washed off in the form of matching tattoos. Apparently Gaga and the 50 survivors made a pact during rehearsals to get a tattoo.
Chicago tattoo artist David Allen shared Gaga's new ink on social media. The symbol stands for "solidarity for survivors of sexual assault."
"Honored to tattoo a symbol of 'unity' on @ladygaga today," he wrote of the image that shows Gaga with the new tattoo on her back left shoulder. "An image of solidarity for survivors of sexual assault."
Many others have posted their matching tattoos on social media, too.
Earlier in the week Gaga hinted that matching tattoos were in the works.
"Tears and hugs, matching tattoos and pictures, storytelling and encouragement," she captioned a backstage image from the Oscars. "These survivors represented for others all over the world and I was so honored to be up there with them. 50+me= 51 #tilithappenstoyou."
Gaga's performance was personal, as she came out in 2014 as a survivor of rape. However, several members of her family missed the story and didn't know she had been raped until the Oscars.
On March 2, Gaga posted a photo of several family members and spoke of her conversation with them.
Gaga said her grandmother and her aunt called me the day after the Oscars because she never told them about her rape.
"I was too ashamed. Too afraid. And it took me a long time to even admit it to myself because I'm Catholic and I knew it was evil but I thought it was my fault," she captioned the image.
"I thought it was my fault for ten years," she continued. "The morning after the Oscars when I talked to my grandmother Ronnie, with tears in her eyes I could hear them welling through the phone she said to me 'My darling granddaughter, I've never been more proud of you than I am today.'"
"Something I have kept a secret for so long that I was more ashamed of than anything-- became the thing the women in my life were the most proud of," Gaga said. "And not just any women, the ones I look up to the most. #BeBrave #speakup #tilithappenstoyou."