The porn video tag "3D Yank" refers to a scene in a 3D animated pornographic video, where the performers are engaging in sexual acts, such as masturbation or intercourse. In this specific case, the term "Yank" suggests that it involves an ejaculation or intense orgasm for one of the characters. The combination of 3D and Yank implies a vivid, animated visual experience in a three-dimensional space for viewers who are into animation and virtual reality porn content.