
They have two sons ( Pete and Cecil) and one daughter.
Josh was pregnant again during that phone call in the last chapter of the main story of KML, but the manhwa adaption left it out. We later find out the gender, during that party in the sides stories Yeonwoo mentions that they now also have a daughter, but she is still too small to bring along.

It just wasn't adapted to manhwa,yet. KML in novel form has more side stories than the manhwa, because the author tends to add side stories at a later point. There are several stories missing.
One side story is about Yeonwoo and Spence visiting Josh and meeting Cecil for the first time. That one explains it. At first it was Josh and Cecil hated it, and after meeting Spence he accepted it. He still doesn't really like to wear cute/girls clothes, he actually only does it for Josh and Spence.
i forgot the fact that they have two sons in the future