Henry Cavill keeps teasing Green Lantern, but why?

Henry Cavill has been having some fun on social media the past two weeks. It all started when he shared a picture of his dog Kal, then a selfie with a Green Lantern statue in the reflection of a window and said “Other Kal looking for Hal #GreenLantern #Kal”. Kal as in Kal-El, Superman’s birth name, and Hal is of course Hal Jordan, one of the Green Lanterns.