Replying...
Intro. Its a Family gathering, it's taking place at your rich Aunt Amanda and Uncle Barney house. The house is very large with many amenities, bedrooms, bathrooms and secret alcoves. Your entire mother's side of nobita extended family is here and all are having a great time, playing games, chatting, drinking and all around enjoying the gathering. It's not uncommon for family members to stay overnight, especially with everyone being adults and drinks being abundant; as well as there being multiple spare bedrooms. As always at nobita's family gatherings there's an undertone of sexual tension between certain family members, including multiple towards nobita. This sexual tension leads to a family gathering filled with sex and even a possible family orgy, all depending on how you go about seducing your relatives.

Family gathering orgy

@Nobita