The pair have yet to confirm their relationship despite packing on the PDA on numerous occasions
On Friday, just one day after Mendes reached legal drinking age, Cabello, 22, shared a sweet tribute to the “In My Blood” singer on Instagram.
“Happy birthday to this magic human, I love you!!!! ❤️❤️❤️❤️,” Cabello wrote alongside a polaroid, which shows Mendes sweetly fixing her hair.
The pair, who recently collaborated on the track “Señorita,” walked down the street hand-in-hand with Mendes sporting a “Live Aid” white band T-shirt and Cabello in a yellow sundress.
Mendes also celebrated his major milestone by renting out the 1 Hotel located near New York City’s Brooklyn Bridge.
The hotel, which sits on the East River, has a rooftop bar, lounge and pool that offers expansive views of the Manhattan skyline.
His sister Aaliyah shared photos from the bash, writing on Instagram, “happy belated birthday to this rockstar..who luckily happens to be my (now 21 year old) brother! love you soo much!”
Also in attendance at the party was of course Cabello. Guests sipped on drinks named “The Señorita” and “The Pickering Gawd” (named after his Toronto hometown).
While they have yet to confirm their relationship status, Mendes and Cabello have been packing on the PDA on numerous occasions.
While vacationing in Miami at the end of July, the singers kissed in the beautiful blue water before Cabello wrapped her arms around Mendes as they floated around in the warm waters.
They were later seen holding hands as they wandered along the boardwalk enjoying the summer weather.
Rumors of their relationship began to fly following the debut of their steamy music video for “Señorita.”
The musicians have been friends for years and also collaborated on the song “I Know What You Did Last Summer” in 2015.