If you actually did that, the Vaporeon would propably die as it is not large enough. This would lead to internal tissue being broken and it basically bleeding out internally. Also, the argument of it having acid armour would not be very good because a human p**is has a lot of sensitive nerve receptors and cells, which would lead to inflammatory areas and a LOT of pain. Another argument against the topic would be that it is able to drown you with water gun if it feels threatened.