This is al i remember

Married couple,
He Retired executive of a family owned manufacturing company (there may have been some dogey dealings with the buyout)
she ?

They come to the UK, for a vacation (can't remember if its to do with Ancestry or visit to friends from service days)

they return home and sell up as they decide to move to the UK

as they are people of leisure, they act on their adventurism in the bedroom to spice up their lives

Hubby slowly and willingly becomes wife.

later they meet a group of ladies that have failed relationships, some violent .....

Hubby becomes advisor to their business venture, after the couple prove their knowledge of the area