Board Thread:Questions and Answers/@comment-27801808-20160215082214/@comment-27701762-20160219031433

Alright, so let me run through the checklist:

- Did not kill any enemies.

- Befriended and did the date/hangout with Papyrus.

- Poured water on Undyne at the end of the chase sequence in Hotland.

To my knowledge, that's what you need to have done in order to get the Undyne hangout to trigger. So if you've done those three things and you're going to Undyne's house and Papyrus isn't waiting in front of it, then it seems like a glitch, in which case you'd need to restart. One possibility is that you need to befriend Papyrus before facing Undyne (the Wiki is not clear on this issue, and I've never gone through without befriending Papyrus, though I'm inclined to experiment), but I don't know in what order you did everything, and I doubt that is the explanation.

The only alternative I can think of would be posting some information from the undertale.ini file so that we can check whether certain flags have been triggered. But at that point we'd require the expertise of someone who knows the game's code.