All the more reason to leave narnia and visit the real world, the more your need grows, the more you are likely to be found out, and as Shelley pointed out then the consequences are likely to be a lot worse than just telling.
Ok I will admit the it is not every partners cup of tea, and yes there will be heartache, but there is more chance of staying together and "dealing with it"
if the truth will out, rather than be found out.