Board Thread:General Discussion/@comment-34732763-20180220195035/@comment-27136653-20180225184159

If it was Alphys and Sans, then who was the one speaking? How do we know it was Gaster?

On the contrary, if it was Gaster, why does it have to be Alphys and Sans? What about Sans and Papyrus?

...

There is no evidence for anything. It's all just headcanons.