Hello, please send me the Bug Report ( check above, at the end of the main page how to generate it), it contains the save files. I will be able to help you and maybe fix this for future players aswell
DoubleDildos are unlocked in BagHeads shop (the guy near the mansion, mentioned above), yet it might not be instant, i think there are a few quests before that. Until that point the player was supposed to gather these from crowd npcs by completing their quests (upon accepting a new quest, check it's rewards to see if it's the desired item).
Sorry for the created inconveniences
Cheers