Sounds just like my DH Moffa.
On the rare occasion we have friends round it won't occur to him to offer them a drink or a chair. I'm constantly reminding him to do things we would consider good manners.
A real problem is his use of alcohol to overcome the anxiety and then he literally won't shut up. Politics, religion, you name it, he'll spout for hours. Last year I took the DC home early from a wedding as he'd had a skinful (I see now it was to overcome nerves) and he had literally backed this poor relative into a corner. woman looked like her ears were bleeding.
It's like a dichotomy between looking terrified and silent or ranting verbal diarrhoea (depending on alcohol consumption).
Today we are sat outside with friends, me chatting to them, him drilling them about the inner workings of their swimming pool 
Last night they laid on an absolute feast of a meal; instead of saying "wow, how lovely" it was "blimey, never seen so much food"
. He just doesn't get that he's being rude and I either just have to leave it or risk a tow.
In the other thread I was accused of clearly hating my husband and being plain nasty. I don't hate him; I want to understand what it is I'm dealing with and how I can support him/myself.