It's kind of strange he resisted the guild master as long as he did, as he seems to have some sort of moral standard, but at the same time he crosses it more easily with strangers than with friends.
He uses it as a tool. He
used the secretary to get her to testify against the prince.
He repeatedly refused the branch director's advances several times because there was nothing he wanted from her, and so nothing to gain by bedding her. Rather it is a bigger mystery why he eventually consented to the idea. Maybe propinquity.
Love potion OP, plz nerf.
...seriously though, if something like that exist there should be a ton of pre-cautionary steps to prevent it, especially for a royalty. I don't know, it's just a small bit that annoys me after seeing these kind of things in hentai I guess. It's not like I really expect a manga like this to focus so much on that anyway.
Probably, but that assumes it is a known issue. If it was a new breakthrough that didn't exist before, or simply something so rare as to not be within the standard realm of consideration, then they would have no reason to believe it needed to be defended against.
There is also the alternative potential: The Princess is the Hero that everyone believes defeated the Maou. There is a good chance most people figure she doesn't NEED defending because she can take care of herself. Resistance to Poison isn't exactly rare for Hero characters in fantasy settings. It just so happens they were wrong this time.
Still, if they don't take precautions against such things going forwards, now that they know for sure it is a vulnerability, then that really would be a silly outcome.
ANYWAY... the Meaou gives off major Lum vibes every time she says "darling"...