For the Church, consummation can only be between the married couple themselves and involves three inseparable elements in one continuous action: (1) the penile erection of the husband; (2) the penetration by the husband's erect penis of his wife's vagina; and (3) the resulting ejaculation of the husband's semen into the womb of his wife. The Church has always held that these three inseparable elements, performed exclusively by the validly married couple, correspond to what God intended to be the only truly human way of engaging in sexual intercourse. No other form of sexual activity, however well-intentioned or motivated or argued, nor any form of medical intervention, constitutes or substitutes for the true conjugal act as willed by God. Nor, therefore, can it be called consummation even in the remotest sense of the term.