Katy Perry wished boyfriend John Mayer a happy birthday on Wednesday, Oct. 16. Credit: Larry Busacca/WireImage

Katy Perry and John Mayer are taking their PDA to a new level! On Wednesday, Oct. 16, the "Roar" singer shared a birthday message with her boyfriend -- and her more than 45 million followers -- telling Mayer, "Happy birthday cutie!" (Mayer turned 36 on hump day.)

Perry, 28, and Mayer recently spent the weekend together in New York for her Saturday Night Live hosting gig on Saturday, Oct. 12, and his brother's nuptials just one day later.

The pair was "beyond affectionate and adorable" at an afterparty on Saturday, a source told Us Weekly at the time. "He was rubbing her back, then pulled her in for an intimate close chat. She put her hand inside his jacket and they were kissing and gazing into each other's eyes."

The couple reunited this past July after a brief three-month split, during which they realized "they must be together," a friend told Us.

"They Skype and text all day," another insider tells Us. "John always checks in before bed!"

Read more about the musical couple's romance in this week's issue of Us Weekly!