Mat...I think so, with certain folks. With others and other situations, a big fat NO.
Couples can get clubby. Especially young married couples. No one pounce on me just yet - yes, it's a generalization, and I think it is rather true. All of a sudden it is 'BBQs, couples dinners, Bob-and-I, kids parties...blah blah snooze'. Single friends 'must be coupled or dated up'. haha. That mentality cracks me up.
But sometimes being single gets you invited places couples don't. Or just being part of couple doesn't, bc some will figure you are busy will want to bring spouse or some other such thing. (married chick who needs to get out of the house and will break free like a total fool, needing babysitting on a night out..you know the ones...can't do anything solo...let's invite her 'next time')
And all in all....so long as you are a person who is somewhat interesting and not totally absorbed in ONE singular pursuit - be it your work, kids, or spouse...there should be no problem regarding being in a couple or no. At least in my experience.
Socially acceptable?? Akh. Half the population roaming about is not social acceptable.