Banana in cereal is good, but like NM11046 said, it needs to be sliced. Not sure I've ever seen anyone 'chop' a banana up. Did the banana sleep with your fiancee?
Is it actually chopped or sliced? If you chop it, that's weird. If you slice it, that's OK.
I remember cereal ads for Total or Special K type cereals always had people throwing bananas, fruit, bit of glass, small explosives, etc., into their cereals.