Well there would be a lot of chronic masturbation and probably a lot more gay sex. Then we'd have one geneartion of men to figure out how to clone ourselves, or make babies wothout women, and finally die out as a race. Does not sound like much fun at all.
If there wasn't any woman, i would create one of those Anime Porno Websites!! lol that would sure make some money in a world like that. ( I said Anime because real porn wouldn't be possible since there would be no women lol)