Genital worship has been argued to be the oldest religion in the world. This makes sense, for those of us with genitals.
Various artifacts showing breast worship date back prior to the earliest written records. In the earliest written religious documents known (those of ancient sumer) the dieties were praised primarily by the praise of their sexual organs, and linguistically this is explicit -- in sumerian, the same word is used for 'vulva' and 'great', for instance.
Even after the popularization of abrahamic religions, magic rites typically are based on stylized representations of the genitals: of the 'magical tools', the wand represents a phallus, the cup represents a vulva, and the pentacle and sword represent the union thereof. The seal of solomon (also known as the star of david) also represents the union of phallus and vulva.
In catholicism, the 'sacred heart' is argued to represent the act of sexual intercourse, and the pictures of a breast-feeding BVM is argued to be a latter-day instance of sublimated breast worship. It is also useful to note the utensils used in a catholic mass, as well as the fact that only male priests are allowed to perform it.