Hello! This is actually a very-common-problem, I would posit; and is one of which to not feel ashamed. There is many a person whom finds themselves escaping by reading novellas, or perusing certain adult media and genres. It is never too late to properly communicate your true feelings. In my view, adultery is the only legitimate reason for divorce, although, obviously, we all, sin and fall short. Therefore, you should not enjoin yourself to a relationship whereby either of you might feel, that adultery is the only way-out, for that is incredibly unhealthy. Logically, you might only find yourselves spiralling against each-other, and being secretive and vindictive, even harbouring resentments. It is only natural, perhaps, to age; to have lessen, our libido, perhaps. We aren't the people we used to be, although many remain unchangeable. Be open and forthright; pursue to what you feel, or you know, you are attracted. Let the other party, your partner, your spouse, your significant-other, know what they mean to you; and that you wouldn't be having said discussion had they been irrelevant or meaningless to you; and, God forbid. But that this is more of a you issue, than one of or for they. Remind them how beautiful they are; what with which you fell in love. However--if this truly be the case, the following--let them know you're uncomfortable with the habits or options you've found yourself doing, or having faced; and that, for the betterment of both of your souls, does the other person agree that, in order to stem a possible tide of possible adultery, even; that you stop, say, utilising "even" adult materials that have somewhat even, replaced your spouse? That you perhaps both stop, therefore, a potential slide in to adultery whereby either of you tire or get bored, whereby it will have been too late? To tell anybody to divorce is quite the sin--however, what I've mentioned, is the only thing justifiable for one, in my opinion. And, so. In order to prevent even adultery from possibly happening, or especially if it's already happened, y'all-two need to at least sit-down and converse about these exact same things and be very honest with the other. Attraction is either there or it is not. Do not, in my opinion, even try to even obsess on the "why," here; this, will do nobody any favours. God Bless.