Bloodchild, by Octavia E Butler. I have never read a story which I found so completely disgusting, and completely beautiful. It is now free on Amazon for Kindle, so get it and read it and be squicked out and moved to tears. Spoilers here, obviously, I am discussing it rather than reviewing it.
It is a story where a creature places its ovipositor into a young man. Left to itself, the grub will eat its way out of his flesh, probably killing him. Yuck. Well, yes: it is not hard to consult our nightmares and produce something foul: a botfly writ large. Making it beautiful is the skill, which after this one free story has me desperate to read more Butler. I have a new favourite SF author above Ursula K LeGuin, Doris Lessing and Margaret Atwood.
How to make it beautiful? There is a symbiotic relationship between the humans and the Tlic. Before, they used animals native to their planet as hosts for their grubs, but increasingly the grubs died. Now, they have found a host which permits the grubs to flourish. In return, the Tlic remove the grubs after they hatch, and nurture the humans back to health. They only use male humans, as they want the females to bear more hosts. At first, they just took the humans, but more progressive Tlic care for their humans, and select the host-male at birth so that they can nurture them into the role.
The human, Gan, chooses to be impregnated. His brother Qui saw a birth, and was horrified by it, and after he was protective and contemptuous of Gan. His sister wanted the honour of bearing a Tlic, and the relationship with the big, strong, beautiful creature with many legs and a sting in its tail which it uses on its host, bringing a delicious lethargy.
The beauty is in the relationship between the Tlic Gatoi and the human Gan, how he resists her then consents, as freely as he may in that situation, for how else will the humans be tolerated on that world? As Butler explains in foreword and afterword, it is a story of symbiosis not slavery. Recommended here, which I found here.