User blog comment:SouthParkClydeFan/Analysis on Lincoln's relationships with his sisters/@comment-26901681-20160919210602/@comment-27447405-20160919222218

I thought about mentioning that, but it was just such a minor interaction, and she had her "because it's unspoken" excuse earlier in the episode before shutting him out, whereas Lisa has an entire episode dedicated to her relationship with Lincoln, which is why it is one notch above it.