Board Thread:General Discussion/@comment-27064008-20160403041313/@comment-27701762-20160403042324

What makes it innacurate, exactly?

There are lines from Undyne about how Napstablook used to hang out with their cousin, until that cousin left. In addition, she comments on you "breaking into Napstablook's cousin's house" if you go into Mettaton's old house. That seems to be about as close to confirmation as you can get without Toby posting it on Twitter or a line from Mettaton saying Napstablook is his cousin (or vice versa).