After 20 years of marriage, such an admission wouldn't have much of an impact. By then you should have a pretty good idea if you are compatible.
But what if she told you this after being together for only 3 months? Does this change your outlook on the relationship? And if so, why?
Obviously, we have a lot rico suaves on gaf, but 20 is still a lot; double the number of total lifetime partners stated in most studies.
I dunno. Maybe I'm old (40ish), but for me, sex and emotion are still intertwined. It is not simply a bodily function that must be satisfied, and the closest warm body would fill the need. It remains the most intimate physical connection between two people.
Maybe the proliferation of porn-on-demand has changed how we perceive/value sex. Don't get me wrong, I love my porn, and maybe if I was single I'd accept any excuse to screw as many people as possible.
But 20 is still a lot.