No offense intended, but you better have a second look at the guy your dating. If that is how he rates what a good wife is, your relationship is doomed at the start.
I've been happily married for 15 years, and good sex is part of a good marriage, but not all of it, not even a majority of it.
Here here. Actually most people get the equation backwards. Step one to good sex is a good relationship. Mind that's a completely different kind of "good" than Cosmo talks about, but I've had both, good relationship sex is the better of the two.