The "good 4 u" singer celebrated her birthday with a simple cake. In a post on her Instagram, Rodrigo smiled in front of the single-tiered creation with white frosting, two candles and "Happy ...

Sami posted a photo of her pink frosted birthday cake with 21 metallic pink birthday ... "Ironically, I hate alcohol," she captioned the snapshot. "Happy 21st birthday to my beautiful Sami girl ...