The title (親戚の子とお泊まりだから) roughly translates to "Because I'm staying over with my relative's child" . It is an adult-themed anime (H-anime) produced by Bewyx .
It’s a cozy read if you like stories about found family, complicated relationships, and slow-burn developments. bewyx shinseki no ko to o tomari dakara
: "O" seems to be used incorrectly here; it could be a particle indicating the object of a verb, but its usage seems off. "Tomari" can mean "stay" or "residence." " Shinseki no Ko to O Tomari dakara