Sorry, I just need to interject here to say that DH and I cruised with DCL last August and we were NOT sat with other couples. We were sat with a family with a young daughter and (almost) teenage son.
Unfortunately, unlike others here, we didn't have a particularly good experience with our table mates and almost considered not going to the dining room at all, after our requests to change tables were denied. However, I wouldn't let that put me off on a future cruise as I'm well aware that we were probably just unlucky with our experience.
OP, I can totally understand why your DH might be reluctant to share a table - by all means make the request and, I'm sure DCL will try to accommodate. However, if you are sat with others, go with an open mind and try to be friendly. You never know, you might end up enjoying it! I don't know if anyone else has already posted this but you are not obliged to go to the dining room for dinner each night - you have the option of eating at the buffet (which I believe has a set menu from one or other of the dining rooms each night). However, it would be a shame to miss out on the atmosphere of the restaurants (particularly Animators Palate) just to avoid being seated with other people.