Responses
i only remember Razoku no Hanayome??? I think it's on the last ch
This is the closest one i can find but they only making out together on the last chapter and didn't fck.
But one of the couple do when on and listen to the other couple fck. I will try to see if i find anything else
https://www.mangago.me/read-manga/endless_after_school_honey/
Got any scenes where 2 couples (eg main and side couple) are fucking together? Not like foursome, but they could be on the same bed type of thing like https://www.mangago.me/read-manga/encirclement_love/nbt/mpn_chapter-2194148/pg-23/