I must admit, "Anber" is confusing in this context.
Ah, 'twas but a House reference. In season 4, House refers to the character Amber as CB, an acronym for Cutthroat Bitch. Of course, C.B. lacks the intelligence and belligerence of Amber, but the rest can still compare.
Often, literally, a pillow fight but may include similar situations like volleyball, particularly when wardrobe is skimpy and the action is bouncy.