Unless the Council shall by unanimous vote, which vote shall be recorded as part of its official proceedings, determine that the best interest of the City shall be served, the following relatives of any elective or appointive officer are disqualified from holding any appointive office or employment during the term for which said elective or appointive officer was elected or appointed: spouse, child, parent, grandchild, grandparent, brother, sister, half-sister, half-brother, or the spouses of any of them. All relationships shall include those arising from adoption. This section shall in no way disqualify such relatives or their spouses who are bona fide appointive officers or employees of the City at the time of the election or appointment of said official.