That's all nonesense, of course you can get bored of sex.
What I would probably say is cut back on it and build up a case of heavy ball-itis.
perhaps spice things up abit, be a bit more adventurous with your locations or spontaneous about when you have it.
dress up, make your partner jealous by giving the impression that someone is attracted to you.
you'd be amazed how much your partner could like you if she believes that another woman may have a chance of taking your attention.
it's all about re-ignition. Anything that is done purely out of routine is bound to get mundane, even sex.
You'd be slightly surprised by how much I do turn it down for the sake of keeping things alive in the future and keeping it spontaneous.
Good Luck