Having been diagnosed with Asperger’s Syndrome 5 years ago at the age of 31 unexpectedly, and having experience with “coming out” to a number of people, I can testify that he’s in a weird situation. Being autistic isn’t an illness, and contrary to what one poster mentioned about not being able to be touched, that’s not at all universal, even amongst those that are more notably autistic than others: some crave being touched, and will go out of their way to be touched, much to the chagrin of others: it’s perverse when you get two autistics together, one wanting to hug constantly and the other one not wanting to hug, because of the hilarity that ensues! It’s not an illness, it’s a neurotype that is different from the majority of the population, but it does not qualify as a mental illness anymore than stating a cat that doesn’t act like a dog is a sick dog.
There are ramifications to coming out (or not) that have long-term results, perhaps good and bad. One of them is I believe in future child custody battles (should things ever come down to that) it’s quite possible to find yourself in a weak bargaining position if you’re considered “defective” in some manner, which only needs to be in the eye of the judge and/or jury, depending on how things are done, or in the eyes of the state, should there ever be any allegations of bad parenting for whatever reason.
Another reason is that often, once someone learns that you’re autistic, they start treating you very differently than before, as though you’re not nearly as capable of understanding at the same level you clearly were before, which is rather frustrating, to say the least.
On the other hand, you might be more fortunate (and this may go along with the previous point as part of a win one, lose one scenario) and have people you tell be more understanding of not subjecting you to sensory nightmares, but it’s also possible that someone less than kind could take advantage of you in that manner, too, and use that against you and not fight fair or treat you right, knowing that something will cause you problems and make you react in a manner that seems all out of proportion to someone watching from the outside that doesn’t understand what’s really going on.
An interesting observation I’ve made is that often people on the spectrum will be magnetically drawn to each other, without conscious thought: what if she, too, is an undiagnosed autistic? I also have an autistic older sister, as well as a nephew, and you can’t be too sure at all times unless you really know someone and their history. The biggest meaningful consistent difference between Asperger’s and Kanner’s autistics is when they start speaking verbally (if at all) while all the other things vary, including the IQ, all over from the low end to the very high end. Speech by itself is a lousy indicator of intelligence, because sensory issues are very important in being able to master the physical ability to verbalize and also to understand verbal speech: if you can’t process audio well enough due to problems making sense of the complex audio of speech, combined with being unable to feel and hear yourself properly to mechanically speak, you could have a high genius IQ, but if people only go by what they can understand as being intelligent speech and communication because that’s the only way they know how to communicate, getting across information is fraught with problems. I personally had to deal with several years of speech therapy, due to not having sufficient control and feeling, not due to not understanding language, and to this day, it’s still not perfect for pronunciation all the time, especially in periods of sensory overload, where things get much worse. Oh, right: where was I going with this paragraph? It’s entirely possible that she fell in love with a lot of his autistic qualities, even if she didn’t have a name in mind to check against. It’s even quite possible that before they got married, she had a solid clue or knew, and just didn’t bother to mention it, for whatever reason. After all, it’s just a check mark if you suspect, and if you still feel the same way after, how much does it matter?
So, yes, somehow he should eventually tell her, perhaps in a more subtle way than coming straight out and telling her, to test the waters and break it to her gently, because it may come as quite a shock, but then again, it may be no shock at all, but now that he’s aware, it does seem he’s accountable for that fact.