There are a number of things in working the SA program that are not optional if I want true sobriety, recovery, healing and freedom--but sex with my spouse is not one of those. The SA literature tells me that sex is indeed optional, and that is how it had to become for me in order for me to be free from resentment toward my spouse.
On August 26, 2009, I sat seething with resentment toward my wife in my living room because I expected we'd have sex after I had just returned from a business trip and hadn't acted out while away. So I picked up my computer and started to surf for porn with her sitting ten feet across the room in front of me. That was the last time I looked at porn, and the next day I started my current period of sobriety from lust. (Looking at porn is an acting out behavior for me, regardless if that's where it stops or not.)
I had no option but to surrender sex with my wife and to have sex become truly optional in order for me in order to find freedom from my obsession with lust. Today I live in a reality in which I surrender any expectation for having sex with my wife, as well as any fantasy about "what it will be like" to have sex with her. I can't engage in any type of sexual fantasy and be sober. Fantasy is never reality, and I must stay in reality. (Incidentally, my resentment is based in my fantasy world as well, so resentment must be surrendered as well.)
The reality is that sometimes we have sex,,but that is something that happens entirely in the reality of where the two of us are at right then. And in between those times, the expectation of and fantasy about having sex are simply surrendered to God.
The White Book sex doesn't lie; sex is indeed optional.