Matt and Foggy were originally characters in a children's book who accidentally got read out (anons choice whether Karen is also a fiction outcast from another story or is a 'Silver tongue' in her own right).

Either: They've made their life in New York while trying secretly for years to find someone to read them back in.

Or: neither have any intention of going back (maybe it was a badly written book, or a grim fantasy landscape of oppression, or even one of them found a copy of the book when they got to the real world, read the end, and has no desire to actually live through their death scene)