Neither the City Manager, the Mayor, the City Council, nor any other authority of the City Government, shall appoint or elect any person related to the Mayor or any other Councilmember, to the City Manager, or to himself, or, in the case of a plural authority, to one of its members, by blood, marriage or adoption within the third degree, to any office or position of profit in the City Government; but this shall not prohibit an officer or employee already in the service of the City from continuing therein.