Question for AITAH Post about rape?

In a AITAH Post, that was deleted, someone asked the question, if he could dose some damiana essence in his wifes water, without her knowledge, to get her horny again after 2 years of no sex that came after the c-section birth of his youngest son and physical pain for her while penetration. If this stuff would work and she would allow him to try, would this be a cause of rape? 100% say so, me too, but this just bothers me and i would just like to have a evaluation.

LOCATION: North Carolina