What I want to convey is that you should not be going through a "song and dance" (i.e., being nice with the expectation of getting sex) everytime the "situation" (i.e., you want sex) comes up. My advice to be nice applies to all the time -- otherwise it's just a ploy, is not genuine.
I'm sure most of you are nice to your wives, and are decent guys. However, everyone gets lazy the longer they're in a relationship -- men and women. You get lazy because you start to believe you're entitled. Men believe they're entitled to sex because why else did they get married? Women believe they are entitled to being treated like princesses by their husbands because why else did they get married?
Think back to how you behaved BEFORE you were getting sex. What did you do together then? How did your treat your then-girlfriend? Do you still do those things together? Do you still treat her the same? You were nice to her because you HOPED you would someday get to have sex. When you got it, you were nice to her because you HOPED that you would keep getting it. You did not EXPECT it like you do now.
Everyone puts their best foot forward to get what they want -- men act like perfect gentlemen, while women lure men in with the promise of sex. When you know you have each other, you get lazy and don't do those things anymore -- then you get resentful because your partner isn't doing what they used to do -- and then you are at a stalemate.
Entitlement is never a good thing -- it makes you lazy and resentful.