Mandingo vs Janine...

On this subject, what's the deal with the 'vs' in many of these porn titles? I always though sex was something you play in co-op mode, not versus.
I see that all over the place in postings of porn videos. I think it is less indicative of a view of sex as a competitive sport than it is of slovenliness and stupidity in the use of language. People see the word "versus" used in sporting matches and carry it over to videos without even thinking of what the word means, namely "against."