Also known as: ひょっとこフェラ, バキュームフェラ, 口交颜, 真空口交
The emoticon that shows the lips being tugged forward on the backwards pull whilst sucking on something, as seen from an overhead or semi-overhead viewpoint. Typically this means Fellatio, but it can also be seen when a character is sucking on a more innocuous object, such as a Popsicle or Pen.
The equivalent pixiv tags are ひょっとこフェラ (Hyottoko fellatio) or バキュームフェラ (Vacuum fellatio).