I'm no way an expert in this, but I've been told it's wrong to think of the expansion of the universe like an explosion where everything moves away from a single point, but rather that the space between each object is expanding, comparing it to the way the surface of a balloon expands (if you were to paint multiple dots on the surface of a balloon they would all move away from each other when you inflate the balloon), though I like to think of it as yeast bread expanding since that's 3d.