it's from the both sides. Sometimes different time the need is different. For me, I do not need my wife to do anything extra. I love the way my wife is now.
however, even people say they will not leave or cheat on the partners might never know the future.
I think the most important thing is to keep the spark going. It's easy now but how about in 10 or 20 years? I hope my wife can stay the way she is. For me, I will always try something new once awhile to keep the relationship fresh.
No matter what happens, I will never leave my wife first.