Link to artist: https://www.pixiv.net/en/users/116134329
Link to doujin: https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_599847/

Please support the artist.

I couldn't find any childbirthing doujinshi about Ai Hoshino from Oshi no ko, so I uploaded one myself.
Caution: this is an AI work.

Story (internet-translated): The hands of an uncle who has obtained a brainwashing app approaches the up-and-coming idol Ai. Brainwashed and doing as the uncle said. After giving birth to twins, the effect of a mysterious app makes my uncle's child pregnant immediately! Give birth immediately! The baby's head comes out, the torso comes out, and the whole body comes out.