It feels like the entire chapter 12 should have been 11.5, since it breaks the continuation of 11 and should (maybe not exist at all), have been much earlier chapter since it is a throw away chapter.
Even tho it is cute as heck, since most of it is a dream sequence and thus actually is pointless, kinda miffed that it exists.
Edit: Reading it in the middle of the night between med doses isnt good. Thought that The Three of Us was just 1 chapter split in to two by the translator, and a lot of translators use .1 and .2 for main chapters, while .5 onwards for omake, so my bad.