Or they ate peanut butter sandwiches, or the wife likes her own cooking.

But, yeah. If the LW was happy before, he can keep doing what used to do. That being said, the answer is so close to right. It shouldn't be Tell her you didn’t realize that she hadn’t learned to cook, as you have not either but Wife, I realise neither of us are good cooks. How do you feel about us both learning together! I found this cooking class / great series of youtube videos / personal mentor."

Or, like you said, they can keep doing their own thing.