In Grand Theft Auto V, Amanda can be seen masturbating with a vibrator. If Michael walks in on her while she masturbates, she will say that she thought she had locked the door, throws it at him, then goes to sleep.
A Vibrator can be found at northwest of Bayside Marina, Bayside. It is next to a scrap bin in a dirt lot.
A second unused vibrator that was meant to appear in GTA San Andreas featured a longer appearance and a whitish grey color. It was removed during development of the game, however, it is possible to spawn it into the game using trainers.