It's dangerous to talk about implied consent when it comes to married couples or long-term sex partners. Even if this man's wife would consent 99 percent of the time, if he tries to have sex and it's that 1 percent of the time when she wouldn't have consented, there is no consent. I agree that his fantasy would be okay if they talked about it ahead of time, as you recommended, I just wanted to caution you against advocating "implied consent." I work with domestic violence victims (mostly women) and I've heard many times from them of being forced to have sex because their abusers believed marriage implied lifelong consent.
Ana in Pennsylvania
Being forced to have sex--being raped by a spouse or a stranger--and being on the receiving end of an attempt to initiate sex by a long-term partner are two different things, AIP, and I was discussing the latter.
To clarify, when I wrote about "implied consent" this is what I was picturing: As much as I might like to, I would never approach a strange man, however attractive he might be, and shove my dick into the crack of his ass without first getting his explicit verbal consent. That would be sexual assault, and it would be wrong. But I do that sort of thing to my boyfriend, gosh, all the time. For the most part, my boyfriend welcomes my sexual advances, doll that he is, and on those occasions when he says no, I slink back to my side of the bed and read the National Review. Did I sexually assault him? No, I have his implied consent to initiate sex whenever I care to, just as he has my implied consent to do the same, and we both reserve the right to say no when we're not in the mood.
And it's that kind of consent--the consent to initiate, even if initiation takes a form that would be regarded as sexual assault if it were attempted on anyone else--that is frequently taken for granted in stable, long-term relationships like mine and TBW's.