Now that we are talking about dreams/nightmares : My brothers friend once started talking about a dream he had, where it was about him living home and his mom had to go to work, but as she said goodbye he asked her if she could leave her pussy home... and she did... and he fucked it in the garage while she was at work. I would have liked to hear more about this, but I was still trying to even understand what he had just told us and everyone were either laughing their ass off or completely weirded out.
Actually met him last year with his mom at the supermarket and all I could think of was him dreaming about fucking her pussy... and if she really had a detachable vagina.