Wait so... she doesn't know about birds and bees?
FUCK! THAT'S...
Now that's even worse... We can't rely on the husband-san to teach her (Though it would be much better that way ( ͡° ͜ʖ ͡°)... so... Sister-san... do us a favor and tell her how to help her husband or he's gonna kill himself one day.
GAAAAAAWD
Hmm... That makes me wonder tho... so is she naturally lewd without knowing about the concept of it...? DAMN.
I know it's the promise of the manga but it's getting kinda boring seeing the same thing happen again and again. He does something she blushes behind his back.
@Snegerd
No we aren't; it's ship-tease that re-uses that same joke every chapter.
But I see this is why ship-tease works — they can actually delude fools that they are close by doing it.