PenSis Twitter Shorts - Ch. 3.5 - Checking the answer

[lesseffective]

I'm not sure what misconception this is trying to dispel. Are there men out there who think virgins don't get menses, or what?

Pretty sure that the implication is that it would only be those having tons of sex all the time that would have a calendar specifically for tracking menstruation for pregnancy risks.

 

[Sollertia_]

Choosing to parody using "pako" was surely an intentional choice