Look at the file name, I got that from CobaltSynapse's Patreon files mixed together with a lot of other random sketches and pictures he made.
It's clearly the same character. It would be weird for him to name it page 12 if it wasn't. plus they're also in bed...in underwear just like the title. Perhaps this is a sketch he made and wanted to keep as a filler page for the comic but never got around to actually progressing the rest of the comic.
Edited at 2019/03/08 19:51:02