I can't imagine how it could be that sex (or most forms of physical activity) wouldn't cause immense pain for people with oripathy. It's basically crystals forming in your body, right? So it could be compared to frostbite without the cold to numb the pain, or kidney stones that could be anywhere in your body.
So look at this picture, but imagine Kal'tsit has glass shards embedded in her breast.
I can't imagine how it could be that sex (or most forms of physical activity) wouldn't cause immense pain for people with oripathy. It's basically crystals forming in your body, right? So it could be compared to frostbite without the cold to numb the pain, or kidney stones that could be anywhere in your body.
So look at this picture, but imagine Kal'tsit has glass shards embedded in her breast.
Internal oripathy shards/lesions exist, and oripathy can exist in multiple body parts at once. Patriot died more shard than flesh, Ptilopsis has them in her brain, Blaze is stated to have them up and down her body, especially her torso, inside and out (and considering the locations, and pattern+color of her body paint in the Great Chief Event, we can kind of guess where the external ones are), and Eyjafjalla has them in her ears and eyes.
Considering Kal actively hides her status and persists entirely through self-checks, its not a stretch to assume that her state would be bad enough to cause worry if more people knew. Granted we can't prove this is the case either, but considering Closure is heavily implied if not outright stated (been a while since I read it) to have been moved up to her position in at least one not-too-distant future...