BEST BIRTH SECRET EVER!
Before heading to Africa, Eun-Tae was studying at a US hospital with his mentor. His mentor was studying the genetics of rare blood types. Eun-Tae provided a full set of samples including sperm. The sperm was not donated to be used in artificial insemination. Yoo-Ha's ex-husband was aware of the research Eun-Tae's mentor was conducting. He admired Eun-Tae and followed his career [stalker-style]. As k-drama luck would have it that same hospital specialized in artificial insemination. Mysteriously a large payment was made to a medical lab technician, and Eun-Tae's research sperm sample went missing. Bada boom bada bang [technical medical terminology], and Eun-Soo is conceived using artificially insemination with Eun-Tae's stolen sperm sample. A unique and clever birth secret is born. I am not a fan of birth secrets, but I like this one.

WORST MARRIAGE PROPOSAL EVER! [Secondary Title]
I am the baby daddy, lets get married. How about next week?