Yes well Diageo the company behind Guinness are none too pleased about this one. It was allegedly made by a 'you tube' user. I suspect this is bollox. The production values are too high for an amateur attempt.
It was probably created by an agency for promotional purposes - their's not Guinness's.
Diageo have asked for the ad to be taken down: although of course - there's no such thing as bad publicity.
It was the same story with the V.W 'unofficial campaign. Whilst distancing themselves from it they were happy to reap the benefits.
The toothed vagina, a concept which was alleged to have been formed by Freud I believe, but is in fact an older myth. This fear is said to be responsible for inadequacy/impotence and misogynism in many males.