Hmmm. you may tell me to butt out, I am only a 22 year old guy, who isint married at all, but my neighbours who are husband and wife act exactly as you describe, it;s always "Ican't take him anyware, or, we cant go anyware fancy 'coz he;d shame me" and I have had experiance bringing girls out to fancy dinners and the like.
(the following might get a little sexist, not sexist in a bad way, but sexist as in generalizing of how men and women behave, what i write is not fact, I;'n not trying t ostart a Men vsWomen debate, I;m just trying to help this guy understand a little better how his soon-to-be-wife most likely sees him in posh socail suituations)
your wife, like many wives or girlfrends (not all though, this is merely a generalization remember) pride themselves on how well they "keep their husbands", then in turn they rely on their husbands to be a rock for them in times of stress or need.
At the moment she probibly thinks you do things like you do just to make her look bad, or becasue you don't really care about her image infrount of other people. To make matters worse you (apparently) sulk about it and things go ever sourer.
Oh the embarrisment!, Instead of having a good husband to rely on, she's got a troublesome child to look after all by herself, all whilst trying to keep up apperances at a very important socail occasion.
I know some things you might be able to do to help things. but first, I assume your wife knows and understands that, as a person with dyspraxia, that you will not act as other people act all the time. and that if she plans to marry you, she must except who you really are.
If she is over stressed about things as innocent as accidentally burping at a table, or munching on a sugarcube, then she needs to lighten up a bit.
When your out and about, it's helps to be open about yourself and your habits; if you grab a sugar lump and eat it and your wife has a go at you, you might do you well to declare openly that you are genuinly sorry "sorry dear"etc. , or perhaps remark about your wife being great for "keeping tabs on you" and that you'd be "compleatly lost without her at social occasions" if your wife sees that you are genuinly sorry and that you're making an effort to show everybody in view that your table manners are not a reflection of her's and that she is infact quite a keen and diligent person, she will probibly end up seeing the lighter side aswell, and instead of feeling annoyed, she will feel vendicated that she has such a considerate husband as to apologise openly the way he does.
you could even use your condition as a talking point in a "matter of fact" sort of way and using it to explain away any odd habits, if your sneeky enough you could use it as a perfect oppourtunity to compliment your wife on her brillient support "even with the little things like manners" etc
I know this sound terribly degrading and sexist on both sides, but if you let your wife know that she is incharge at socail occasions and that you are comforted by her constant reminders on how to behave, she will have a better sense of control and a sense that you are working with her instead of against her,
She will lose the hard-to-control teen that caused her so much stress (and reflected badly on her), and she will gain a supportive and understanding, but slightly wild husband who relies on her to keep him straight(which reflects quite well on her).
