Jack only asks "Y/n, whos this?" at the end of the demo when he comes out of the room to find you and Shaun hugging. There is no after that since that is where the demo ends. This end does not change no matter what choices you make.
There is an after story when you complete the game along with four tapes for lore. In the afterlife/afterstory it is when you and Ian are first moving into the apartment together.
The tapes range from a couple of things that i wont mention here.