To masturbate only using one's mind. Titillation comes from stimulation of the brain. Ejaculation often indicated by concentrated spit being ejected from the mouth.

To masturbate to someone using your mind, not your hands.

Being so aroused by the characters, events, or interactions on Criminal Minds that your body brings itself to climax of its own accord.

Mindsturbation is a combination of motivation and temporary mental stimulation.

The act of using one’s mind or memories to expedite the process of sexual stimulation; hands-free self-pleasure that stems solely from thoughts