Danjo-hi 1:39 no Heikou Sekai wa Omoi no Hoka Futsuu (Fan Colored) - Vol. 1 Ch. 9 - Let's go to the convenience store.

[MangaDex]

 

[MrTurtleMan]

"Sou, are you crazy going to the convenience store by yourself?" Sumire asked calmly

She's scared of him getting attacked by thirsty women that she pushes him down whilst also being the girl most strongly aiming for his virginity

 

[Auretor]

Sorry Sumire but his first time was given to Mama

 

[Geako]

Sorry Sumire but his first time was given to Mama

Didn't it happened with Sumire?

 

[arcsalvo]

This is a bit late, but since this is a parallel universe, it seems to be one where inbreeding isn't problematic. Or if it is, it's a lot less problematic than our world.