You know you said someone reminded you of an alcoholic you once knew?
You remind me of a bigot I once knew.
For goodness sake if you went to a B&B with your wife would you expect to be offered 2 separate rooms while everyone else was given the accommodation they expected?
Heterosexual marriage is universally accepted, but not everyone is comfortable with gay partnerships.
They clearly intended to victimise them as they singled them out for different discriminatory treatment.
That is your perception of their motive, but as I said, if someone needs to do business to make a living, they are more than likely to do all they can to satisfy a customer, so should be assumed to be acting sincerely (edit: ie without intending to victimize them) unless good reason is provided that they weren't.
Why are you bothering to argue in favour of discrimination?
I see no difference between the men in this case and a straight couple who aren't married, and I think the B&B owners had the right to decide whether to offer them double beds or single.