https://www.dlsite.com/maniax/work/=/product_id/RJ01556279.html
https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_727444

New series.
Sucks to be MC, his wife is bitch who cheats on him, his step daughter looks prim and proper but she is starting to behave like her mother and despite being in middle school she was already looking for a partner, MC who has already lost it goes to check if she's still a virgin.
He ends up taking her first time.

My question is how does he even get cheated on despite having such a massive dick?

Base +24, qwerty5715 +6