Multiverses and Balloons

Our universe is expanding. That expansion is accelerating. To explain this we look within our universe and say there must be some sort of repulsive energy we do not understand that is causing this expansion = dark energy. 

I am drawn to the word expansion. I think there is a big clue here. Our universe is expanding - into what? 

I’d guess into a multiverse containing other universes. Furthermore I’d suggest our multiverse neighbors are acting on our universe in a manner that is causing it to stretch outward in all directions. 

If true then “dark energy” is really geometrical distortion -resulting from the effects of extra-universe forces. 

As example imagine our universe is a balloon floating in the middle of a room. The pressure in the balloon is the same as outside it, and therefore the balloon is static - neither expanding or contracting.  

Now imagine the air in the room outside the balloon is being withdrawn at an ever increasing rate causing the pressure surrounding the balloon to drop. The balloon would then expand at an ever increasing rate, everywhere, into something we could not directly experience.

Since we could not directly experience what is occurring outside of our balloon universe we would look for repulsive energy within - our dark energy - to explain our expansion.  But in reality our universe would be expanding due to changes occurring outside of our universe = no dark energy required. 

If true, despite not being able to experience anything outside our universe,  we could still detect the effects a multiverse has on our universe - telling us a great deal about the nature and structure of the multiverse, and explaining our own expansion.