For those who's still not getting the main point. Bethany didn't die, Namjoon saved her from that sad thing. Taehiso, didn't say 'I love you too' to his Mom because he's still thinking those things that might happen. He's still not sure if he still can recall her Mom or not, but he is.
***
another thing, there will be a part 2 but— that will happen IF.YOU.STILL.WANT.TO.HAVE.IT. Now let me hear your decisions!!!! Cooperate with me aye! Love you