She doesn't know.
I'm not going to say that she wouldn't like it if she found out, but it would just be more evidence that my views on sex are weird (her opinion, not mine). She wasn't always like this; heck, when first married we even had a subscription to Penthouse and she enjoyed the letters as much as I did. And, then, there was the couple of years during which we engaged in multiple threesomes as well as the occasional solo meetup with one of her three fuck buddies.
But the last five years or so in particular our views of what constitutes a "great" sex life have diverged to the point that I no longer derive much pleasure from the occasional fuck and actually consciously avoid it entirely.