Article here. Excerpt:
'"I think for a lot of men, they just feel so much pressure it really sucks all the enjoyment out of it; it's sort of like your wedding day in a lot of ways," said Lisa Daily, a Sarasota-based dating expert and author. "I think for a lot of people it's a sort of do-or-die day, and instead of judging the relationship on a whole, we judge it on a night, and there's a 15-step process and if you get any of them wrong you're in big trouble.
...
The pressure on men comes from many sources, including the advertisements of jewelers, greeting card companies, florists and chocolate makers. But Daily said the expectations of wives and girlfriends fuel the process.'