Spiritual intercourse would mean something more specific than universal love. It would be special communion with the sexually complementary; something a man can have only with a woman and a woman only with a man. We are made complete by such union. The souls in heaven must still take on the aspects of male and female to make spiritual merging and the ecstasy of merging with another compatible soul joyful and glorious

The relationship need not be confined to one in Heaven. , monogamy is for earthly union.
The relationship may not extend to all persons of the opposite sex, at least not in the same way or degree. If it did extend to all, it would treat each differently simply because each is different-sexually as well as in other ways. I think there must be some special ``kindred souls'' in Heaven that we are designed to feel a special sexual/ heavenly love for. That would be the Heavenly solution to the earthly riddle of why in the world John falls for Mary, of all people, and not for Jane, and why romantic lovers feel their love is fated, ``in the stars'', ``made in Heaven''.  As there are no wicked minds in heaven, I believe God does not put restriction on his perfected heavenly creatures. There are countless soul mates for each person or soul, spirit to experience blissful union and pleasure and it would be boring and meaningless to be confined to one or a few partners given that we have exist in an eternal moment of the ever changing now. “Not this is just something that seems logical to me, not something I know for sure:

It would not feel apart from or opposed to the God-relationship, but a part of it or a consequence of it: His design, the wave of His baton. It would also be totally unself-conscious and unselfish: the ethical goodness of agape external, and without selfishness or animal drives.

We know Heaven by earthly clues. Let us try to read all the clues in earthly intercourse. It has three levels of meaning: the subhuman, or animal; the superhuman, or divine; and the specifically human. (All three levels exist in us humans.)
Specifically human reasons for intercourse include the desire to express personal love. As to the first, there is no marriage in Heaven. As there can be no wrong in heaven spiritual, union between any souls like soul must happen.

I think there will probably be millions of more adequate ways to express love than the clumsy ecstasy of fitting two bodies together like pieces of a jigsaw puzzle.

This spiritual intercourse with God is the ecstasy hinted at in all earthly intercourse, physical or spiritual. It is the ultimate reason why sexual passion is so strong, so different from other passions, so heavy with suggestions of profound meanings that just elude our grasp. No mere practical needs account for it. No mere animal drive explains it. No animal falls in love, writes profound romantic poetry, or sees sex as a symbol of the ultimate meaning of life, sexuality is a foretaste of that self-giving, that losing and finding the self,. That is what we long for; that is why we tremble to stand outside ourselves in the other, to give our whole selves, body and soul: because we are images of God the sexual being. We love the other sex because God loves God.

In addition, this earthly love is so passionate because Heaven is full of passion, of energy and dynamism... Earthly sex is the shadow, and our lives are a process of thickening so that we can share in the substance, becoming Heavenly fire so that we can endure and rejoice in the Heavenly fire of eternal spiritual sexual union with any soul mate we desire.
Please I am not being dogmatic on this topic but just put it out there for discussion and dialogue.

Regards
Alan