It is an expansion. But as has been pointed out to you, the overall expansion of space has nothing to do with what happens on a local level.
The analogy to a ballon, like all analogies, presents an incomplete picture. There are also local events, and we see them. We can see new stars being formed, old stars dying, things colliding. The univese is dynamic and changing and old, very old.
Aslan is not a Tame Lion