1. The substance comprised of lotion, spit, and semen which can be found near a computer keyboard as a result of rapid masturbation. After being left for an extended period of time, they become kitty deposits as whoever left them there blame animals as the cause of the mess.
2. Basement lurker masturbation
Matthew neglected to clean up after he masturbated, leaving the lotion and semen all over the keyboard. His excuse was "the kitties must have left that there, those are kitty deposits."