Shawn Mendes is no longer keeping his relationship with Bruna Marquezine off social media.

After months of sightings and speculation surrounding the singer and Brazilian actress, Mendes made their romance Instagram official on Aug. 4 with an emotional tribute celebrating Marquezine's 31st birthday, telling her that she had changed his life and publicly declaring his love for her in Portuguese.

“Feliz aniversário my baby,” Mendes began.

The 27-year-old singer described Marquezine as “a light” and “a mãe in every room” she enters, using the Portuguese word for mother while praising the way she cares for the people around her.

“Not to be tooooo sappy but you've truly changed my life and I am so so grateful for you,” Mendes wrote.

He then ended the message with the declaration that left little ambiguity about their relationship: “Eu te amo muito muito muitoo!!!” — Portuguese for “I love you so, so, so much.”

For Mendes, who has become increasingly private about his relationships in recent years, the post marked a significant change from the way he and Marquezine had handled their romance publicly up to that point.

The two hadn't exactly been hiding from each other. They simply hadn't been saying much.

Months of Romance Rumors Came Before the Post

Mendes and Marquezine were first romantically linked in late 2025 after they were spotted spending time together in Brazil. As additional sightings followed, fans began piecing together what increasingly appeared to be a relationship.

By January, their connection had become considerably harder to describe as just a rumor.

The pair were photographed together during a grocery-shopping trip in Los Angeles on Jan. 7, where they were seen embracing repeatedly and displaying affection toward one another. In one photograph, Mendes wrapped his arms around Marquezine from behind, while another showed him embracing her from the front.

Those photographs provided strong public evidence of a romance, but Mendes and Marquezine continued to keep the details largely to themselves.

That changed with her birthday.

Rather than allowing photographs or unnamed sources to define the relationship, Mendes used his own Instagram account to publicly express how important Marquezine had become to him.

The post included photos and videos showing Marquezine spending time with children at Casa Amarela Providência, a cultural and educational center in Rio de Janeiro. Mendes thanked the organization for its work while sharing moments from the visit.

He also shared additional images of himself with Marquezine through his Instagram Story.

Mendes Has Become More Protective of His Relationships

The public declaration stands out partly because Mendes has previously explained why he has become reluctant to share his romantic life online.

During a 2024 appearance on Jay Shetty's On Purpose podcast, Mendes said he had largely stepped away from social media and tried not to pay attention to online discussion surrounding his relationships. He described that outside attention as potentially harmful to the relationship itself and said he had become “pretty strict” about protecting that part of his life.

Marquezine has expressed a similar instinct toward privacy. The actress previously said she had learned to keep parts of her life to herself rather than feeling pressure to prove anything publicly.

That made Mendes' Aug. 4 message considerably more notable than another celebrity birthday post.

It was a rare instance of him choosing to define the relationship publicly.

Who Is Bruna Marquezine?

While Marquezine may be less familiar to some of Mendes' North American music audience, she has been a major entertainment figure in Brazil since childhood.

Born in 1995, Marquezine began acting at a young age and appeared in numerous Brazilian television productions, including Mulheres Apaixonadas, América, Cobras & Lagartos, Em Família, I Love Paraisópolis and Deus Salve o Rei.

She later expanded into international film, playing Jenny Kord in DC's 2023 superhero movie Blue Beetle. She has also worked behind the camera, serving as a co-producer and co-director in addition to starring in Amor da Minha Vida.

Marquezine previously had a high-profile, on-and-off relationship with Brazilian soccer star Neymar between 2013 and 2018. She later dated actor João Guilherme before their split was announced in early 2025.

Mendes' best-known previous relationship was with Camila Cabello. The two began dating in 2019, split in 2021 and briefly rekindled their romance in 2023 before separating again.

His relationship with Marquezine has unfolded much differently in public.

There was no major joint announcement when the dating speculation began. Instead, sightings accumulated over several months, followed by photographs showing the pair openly affectionate together.

Then came Aug. 4.

With a birthday message, a collection of personal moments and four words in Portuguese — “Eu te amo muito muito muitoo” — Mendes finally put the relationship on his own social media and told Marquezine, and everyone watching, exactly how he felt.