Why does my Aspergers husband love to criticise? or Light conversation over dinner - Aspergers-style

It all began wonderfully.
I arrived home from work and not only had Ethan fed the kids and got them in the bath - he also had our dinner smelling tantalising in the oven. He was rather pleased with himself and I was very pleasantly surprised.
Then we sat down to eat - no TV, no kids, no radio, just me and him and our dinner. And it all went wrong.
I have an interview on Friday so, after a bit of small talk about him and his day (steered by me), Ethan asked me if I was feeling ready for the interview. Except that the way he phrased it - rattling off what he felt I should have done in preparation, and raising his eyebrows at my answers, just got me irritated. I know I should be able to rise above tone and delivery by now, that I shouldn't put too much store on it - but just as Ethan's brain is wired not to detect tone and body language, mine is highly wired to notice all of this in detail and form a conclusion based on it (which, in Ethan's case is often not what he means at all).
I suggested we change the subject - quite controlled and grown-up of me, I thought. Ethan came back with: 'So how's the card-making business going then?' (a wild notion I had a few weeks ago to start making my own greetings cards in my 'spare' time). Ethan knows I've done nothing. And possibly his opening was a purely innocent way of encouraging me to share my thoughts on the project and revive my enthusiasm. But it sounded very much to my ears like a highly-charged critical question.
We changed the subject again.
This time the discussion was based around us needing to spend more time together - just hanging out, having fun...surely nothing could go wrong with this topic of conversation. 'Well this morning at church was a complete waste of time. We could have used the morning to have much better quality time together,' said Ethan.
Argh. I took the moral, indignant high-ground: 'Will you stop being so b***** negative and critical about everything? Everything we've spoken about you've taken a critical slant on. You've made the effort to cook dinner and get the kids out of the way but what's the point if you're just going to spend the time getting at me and moaning? This is meant to be us having a happy time together.'
Ethan smiled his biggest fake smile. 'We are having a happy time...' followed by a shout that a caveman would have been proud of to 'get back upstairs' directed at Ava, Sam and Oliver who had chosen this moment to appear en masse at the dining room table - seemingly for no apparent reason other than to further irritate the situation.
Dinner was cut prematurely short after that as we'd run out of things to talk about, the kids had started whining and it was time to get them ready for bed anyway.
But before bedtime proceedings began - we had a couple of minutes to analyse what had gone wrong - and a key element in us being able to do this was that neither of us let the depressing conversation drag us down too much. We laughed at ourselves - well, smiled wryly at least, and defused the mood.
And Ethan ended our short time together with a joke - yes, he really did: suggesting he use Aspergers flash cards depicting mood/feeling/emotion that he could select at will and hold up as he spoke - just to avoid any confusion in the future. Or maybe he was serious. Perhaps there's a market there...