User blog comment:MaverickGuy720/My Take On Not A Loud/@comment-24200891-20170930055239

I don't think the episode is about Lincoln being adopted. I guess the episode is about Lincoln being forbidden to do something or know something much to his annoyance, because his sisters can do this. So he tries to do this in secret. The plot would be similar to "The Trouble with Scribbles" of "Foster's house for imaginary friends".