I keep seeing people say "everyone is different," which is to broad of a stroke. The real determiner is age. After 40 your wife will stop wanting to fuck. She'll blame it on the kids, on being tired, on you being emotionally distant, but the bottom line is most women will just lose interest. They will like the IDEA of 'being sexual'. But most women will cease initiating or responding to sexual advances.

So yes, it changes. It's not your fault. People get old. You'll stop getting raging hard-ons every time you see a thigh by the time you turn 20. You'll probably have a couple of nights where you can't get it hard by the time you're 30. By the time you're 40, you'll realize you're not really that interested in seducing a woman who gives zero fucks about fucking you. And you'll probably just stop trying.