Why fuck with a good fantasy?

I recently read a blog post entitled "The Joys of Theoretical Non-Monogamy," at Greta Christina's blog http://gretachristina.typepad.com/greta_christinas_weblog/2008/05/the-joy-of-theo.html

Here's a key realization she makes:
"When you're monogamous, every single person you're even moderately attracted to seems like Shangri-La, a lost city of infinite erotic promise, with genitals made of divine light and chocolate ice cream that would transform your life if only you could have a taste. (It did for me, anyway.) The allure of the forbidden, and all that. But when you're non-monogamous, you remember that you don't actually want to go to bed with every attractive person who crosses your path."

I couldn't agree more! Sexual fantasies are better than reality. So my attitude is, why spoil a good fantasy with reality? I love my sexual fantasies. So I protect them from reality. I love them because they infuse my everyday life with a jolt of positive energy. So I want them to retain every speck of their power. That way I can rely on them to always have their way with me. I never want to become wise and prudent with them. Indeed, I want to remain their captive? It’s like having my very own individual stimulus package. Am I an addict? Absolutely! Whenever I need a hit I just dial one of my fantasies up into my brain and wham-oh, I’m transported to that little piece of portable euphoria where everyone or everything that I desire sexually is granted. Why would I want to fuck with that by diminishing it with reality?

How do you think the freedom to fantasize affects your relationships?