VIDEO : Kendall Jenner Adds Naughty Message in Birthday Cupcakes to Hailey Baldwin

Bestie to Hailey Baldwin, who celebrated her 19th birthday Sunday, Kendall Jenner had some very personalized cupcakes sent to her gal pal. Baldwin posted (then deleted) an Instagram photo of a box of what appear to be Sprinkles cupcakes from her gal-pal, which included a naughty four letter word messaged on top. Baldwin captioned a photo, "Birthday cupcakes from @kendalljenner. What else are friends for?"