I'm kinda worried about Dynasty Warriors 9. It's supposed to be open world, and I've yet to find an open world game I've actually liked except for Far Cry 3 Blood Dragon (Though I only really liked that due to the ridiculous 80's ptesentation. I didn't like the gameplay much at all).
They had to be using a fake dong with a pump, a well hidden hose attached to a pump, or one of the "self inflating" balloon tricks to create the illusion of that happening.
That is not possible by normal means.