The Weight of Duty

Prompt: First time but a little kinkier with a family member maybe as a 'showing the young one(s) how it's made' story. oh and dubcon would be nice.

Summary: Now that the twins are of age, their uncle takes them in hand to teach them their marital duties. But the experience will be very different for each of them.

Warnings/enticements: Dubcon, humiliation, uncle/nephew, twin/twin, arranged marriage, body modification, forced surgery. No mpreg.