One day, a mother is shocked when she walks in on her son masturbating. Not by the fact that he was masturbating, but by the size of his penis. Or rather, the lack of size...
Considering purchasing a copy to support the author if you enjoyed it https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_149436 https://www.dlsite.com/maniax/work/=/product_id/RJ246396.html
This version is from fanza, but from what I've noticed the mosaics on the DLsite versions can be slightly better.