最初の実験では、極端に小柄な女の子の小さすぎるお尻の穴の中にいくつかのアイテムを設置することに成功しました

Sooner or later every asshole must work properly and it's newer too late to start experimenting. If fear is big then the item must be smaller and step by step fear gets smaller and items in the ass get bigger until it's ready for cock