https://www.dlsite.com/books/work/=/product_id/BJ141559.html
Looks like a sequel series to Pai☆Panic ~Hasamareta Dekapai~ (ぱい☆パニック ～挟まれたデカぱい～) also by Inkey. The sequel has four chapters, the original has 16, though none after 10 seem to be available online (so requesting those too if possible).