(as) sweet as pie
Particularly sweet, friendly, or kindly. My grandmother, God rest her soul, was sweet as pie, but boy could she tell some raunchy jokes! The kids may seem as sweet as pie right now, but they can be little terrors when they want to be.
sweet as pie
mainly BRITISHIf someone is as sweet as pie, they are very kind and friendly. A black-hearted villain in the latest Bond film, in real life he's sweet as pie. Compare with nice as pie.