Help please Dog licking furniture - attachment disorder?

[Sunnymeg]

We have a 7 year old Cavalier King Charles spaniel. I am home the majority of the day every day, apart from school run, shopping etc. Over the last few weeks he has started licking the furniture, but only the items that my husband sits on/ uses. He is walked every morning straight after my husband has left for work, but as soon as we come home he starts mooching about and licking my husband's chair.. He will lick all the parts of the chair even the back if it. This goes on for about 20 minutes and then he settles down and is fine the rest of the day. I have tried distracting him but with little success.

I am thinking this is some sort of attachment disorder, but am at a loss as to why he has suddenly started doing this. He was a rescue dog and we are his third owners, but we have has him for over five years.

Can anybody help?

Thank you