The porn video tag "cd-masturbation" refers to a specific type of content involving two key elements: 1) CD, which is an abbreviation for "Compact Disc" and could also stand for "Cum Drenched," depending on the context; and 2) Masturbation.
In this context, it suggests a scene where a person uses a compact disc (possibly as an unconventional sex toy or in combination with other objects) to masturbate. The term "Cum Drenched" can be used to highlight the amount of semen produced during the act of masturbation, indicating a high level of sexual excitement and satisfaction.