I mean, would any of them really be that upset?
tldr: at the sex (itself, alone) I sincerely doubt it, at the circumstances that caused the sex, that's the question.
Depends on what you mean by "upset"... And the exact effect of the "lust" spell. If the spell controls them in any way, or intoxicates them to the point of effectively blacking out (losing reason until they wake up later), as opposed to simply increasing their preexisting lust (simply) to the point of saying "eh, to hell with it." then I can certainly see them get angry, depressed, etc.
Loss of control is loss of control. If you are forced to do something, even something that you might want to do under different circumstances, you have every reason to be "upset."
On the flip side, if the spell simply takes their preexisting natural desire for him (and his for them) and just ramps it up a "few notches," so that something that they planned on doing, say, later that night, they decided to do immediately... I doubt they would be upset.
There is a clear difference between (one of or) two people talking an aphrodisiac intentionally to "stimulate" their desire, and one or both having the aphrodisiac forced on them. An event that was planned, or otherwise spontaneous (but still accepted intentionally) is VASTLY different than something you suddenly wake up from and
realize what you did (regardless of how you would react to it under better circumstances).
It's why drunken sex can be called rape, even if
both parties were "black out" drunk. Both people may have gotten married under better circumstances, but any potential relationship is destroyed by the consequences of unintended "relations." (i.e. either one can claim that they were forced because they were not in their right mind).
Anyway, I have basically said the same thing three different ways.
I don't "disapprove" of the series
in any way, but I would have preferred that they didn't pull (what may or may not be) an oopsies, and I'm not referring to the pregnancy...