Also known as: 即堕ち2コマシリーズ, 即堕ち2コマ, 即落ち2コマシリーズ, 即堕ち, 即堕
A trope where a character is almost instantly defeated, despite their cocky attitude beforehand. Often a sexual scenario where a character ends up Mating Pressed despite their protests that they'll never lose to the dick, although it can also apply to non-sexual scenarios.
It most often follows a 2koma format, with a jump cut between the before and after panels, although it can also be a Segmented Comic spread across multiple separate posts.
Pixiv Encyclopedia said that it started as a personal webcomic series by a certain artist. After that, however, the original webcomics were deleted for some reason. The series name is now used as a general tag on Pixiv.
Just because a post depicts an SFW scene followed by an NSFW scene, it doesn't necessarily mean it's an "instant loss" situation.