I'm looking for a page of a manga I saw out of context. It depicted a theater that was showing an otaku-focused anime movie, a lowbrow ecchi comedy, dialogue along the lines of "No onii-chan not there" etc. The actual focus of the scene was a normal person sitting in the theater, looking around at all the otaku laughing uproariously while he was confused at what the joke was even supposed to be. This was framed in such a way that this all was clearly bizarre and uncomfortable for the normal guy.

It was a single page, black and white. Saw it at least a couple years back. Not heavily stylized; characters were at least semi-realistic and not blobs or something. Please and thank you.