LOL. I was only being silly given that there is technically two meanings to that statement which are (I beleive) intentional, hence the need for the grammar. Rather than being bad grammar due to your local kids being ignorant it may actually be bad grammar as a legitimate use of the poetic license.

Anyway, you can fuck during a period. If you want to. Though some men (lesser men than I) have willies that faint at the sight of blood

It does remind me of a bad vampire parody which was so bad I cannot remember the name of it or who was in it apart from this one line: Woman: I can't, I'm on my period Vampire: Result!