what type of relationship existed between the van dans and the franks

Mr. Frank and Mr. Van Daan were business associates. An arrangement was made for them to stay with the Franks in their annex. Part of the arrangement was financial. Anne isn't crazy about Van Daan, but she does eventually find a little romance with his son Peter. Mrs. Van Daan is a pistol, very vain and very selfish. She doesn't relate well to children, but she does indulge in a bit of flirtation with Mr Frank (not reciprocated).