Skunk has a gum, but after swallowing the gum it can contain inflation and other effects, which in addition to the gum expanding outwards, it expands inwards, thus generating inflation. The possum cannot tell about the purpose of what it will do or what will happen, and if the human refuses, it will force it until it swallows. There is no possibility of exploding as much as possible. The skunk gas that was in the gum also inflates which makes the gas enter the body after swallowing.