The porn video tag "gay jerk off" refers to a category of adult content featuring homosexual male acts. In this case, the term "gay" specifies that the participants are men engaging in same-sex activity. The act of "jerk off" or "masturbate" implies that the focus of the video is on the sexual stimulation and release of the individuals involved, without any penetrative intercourse. This type of content is meant for an adult audience who are interested in watching homosexual male masturbation and arousal.