I think that "holy" or rather completely spiritual sexuality can be summed up with one small phrase:
"...Love consists not in feeling great things but in having great detachment [from oneself] and in suffering for the Beloved...All for you and nothing for me..."
- Saint John of the Cross (1542 – 1591), Catholic mystic
If a lover has the attitude, "
all for you and nothing for me" then sex is a holy act capable of fostering not only spiritual growth but even detachment from self; in truth it also becomes
seva and can bring a person into union with God.
To achieve this selfless state of sacrificial love in one's sexual relationship, I would encourage some reading of one of my favourite books of the Bible -
The Song of Songs/Song of Solomon.
It is a story of the love affair between two unmarried youngsters, probably in their mid-teens, living circa 900 BC in Ancient Israel. Contrary to the marriage rites of their time, which were arranged according to class and which were only about property rights and succession, the love between these two youngsters ascends to the sacramental level - it is a mutual, self-giving, committed relationship founded upon love alone between a nobleman's daughter and a shepherd boy. In this respect we have a true marriage so to speak, a union of two souls, a sacrament not just a ritual and property rights. The poem is told largely from the woman's perspective ie during the oral sex scenes it is the woman's who speaks of tasting the man's fruit (semen) and the woman who speaks of the man blowing upon her garden (vagina). This was revolutionary for the time. In the narrative they have to make love and kiss in secret, and the young girls brothers and other antagonists often intervene to keep the two lovers apart but they stick together through thick and thin. Note how she affectionately calls him her "king", and later on in the text the boy chides/mocks the real King Solomon for all his concubines and wealth. The girl has her own king in the Shepherd boy and he has his own wealth in the girl, with no need for thousands of concubines, gardens and riches. His girl, according to the text, has it all!
I love it. I suggest one to read it alone in translation rather than in the available Bible translations:
Amazon.com: The Song of Songs: A New Translation (9780520213302): Ariel Bloch, Chana Bloch, Robert Alter: Books
(But if you own a Bible then do just skip right back in your Old Testament to this book. The translation will still be good, even though a singular translation like the above naturally gives it more focus in expression and artistic quality)
"....Kiss me, make me drunk with your kisses!
Your sweet lovemaking
is better than wine
You are fragrant,
you are myrrh and aloes.
All the young women want you.
Take me by the hand, let us run together!
My lover, my king, has brought me into his chambers.
We will laugh, you and I, and count each kiss,
better than wine.
Every one of them wants you.
...
My brothers were angry with me,
they made me guard the vineyards,
I have not guarded my own (She has been sexually active)
My king lay down beside me
and my fragrance
wakened the night
All night My beloved is to me a cluster of myrrh
that lies between my breasts.
My beloved is to me a sheaf of
henna blossoms in the vineyards of Ein Gedi
...
And my beloved among the young men
is a branching apricot tree in the wood.
In that shade I have often lingered,
tasting the fruit
...
Now he has brought me to the house of wine,
and his flag over me is love.
Let me lie among vine blossoms,
in a bed of apricots!
I am in the fever of love.
His left hand beneath my head,
his right arm
holding me close.
Daughters of Jerusalem, swear to me
by the gazelles, by the deer in the field,
that you will never awaken love
until it is ripe.
...
Awake, north wind; O south wind, come,
breathe upon my garden,
let its spices stream out.
Let my lover come into his garden
and taste its delicious fruit.
I have come into my garden,
my sister, my bride,
I have gathered my myrrh and my spices,
I have eaten from the honeycomb,
I have drunk the milk and the wine.
Feast, friends, and drink
till you are drunk with love!
...
How wonderful you are, O Love,
how much sweeter
than all other pleasures!
That day you seemed to me a tall palm tree,
and your breasts
the clusters of its fruit.
I said in my heart,
Let me climb into that palm tree
and take hold of its branches
And oh, may your breasts be like clusters
of grapes on a vine, the scent
of your breath like apricots,
your mouth good wine-
That pleases my lover, rousing him
even from sleep.
I am my lover's,
he longs for me,
only for me.
Come, my beloved,
let us go out into the fields
and lie all night among the flowering henna.
...
There I will give you my love..."
- The Song of Songs, Bible (Ariel Bloch translation)