credit for the translation goes to Deranged of the touhou image board
Also Youmu is moe~

I'm shocked for that Rinnosuke wasn't pervy this time.

In this doujin girls are preparing to be pervert, not Rinnosuke.

WTH IS WITH THIS DOUJIN?! *continues reading though*

Oh God, Youmu is so adorable, here.

... If I marry Yuyuko, can I get Youmu as my step-daughter?

Youmu said:
Then... at once.

Seems like kind of an awkward translation to me. But then again I don't know enough Moonspeak yet to make that claim with any weight.

This Youmu is fucking adorable.