Bum or Cherry?

Adam has a slight cleft in his chin (whenever I say that phrase I always think of Gaston in Beauty and the Beast because it's in his song).

The other morning Zach climbed in to bed with him (Adam, not Gaston...) and squeezed his chin together from the sides.  He giggled a bit and then excitedly said "you have a little bum!".  But to add to the cuteness, anyone who has heard Zach talk will know he has quite an idiosyncratic way of speaking, where he lengthens the last syllable of a sentance, especially when tired, which he did on this occasion so it came out more like "you have a little berrrrrrm!".  Then went around all of us squeezing our chins to see who had bums and who had cherries.