Having a kid with your sibling is a pretty weird, socially frowned-upon thing to do except in a few scenarios. Like this one: Samuel Leighton-Dore, 24, is a gay man who plans to use IVF treatment, and some help from his sister's eggs, to have a kid who is a genetic combo of him and his partner.

"The only possible chance my partner and I have of waving our respective biological flags in our future kid's DNA is if my sister donates an egg for my partner's sperm," he writes in a post for parenting blog Mamamia. "No, she won't be carrying the baby—just offering up the bun for another yet-to-be-determined woman's oven."

Sources: Mamamia