“I’d be careful with that kind of joke, Professor,” Toby warned. “Sisters of Avei consider the use of love potions a form of rape. So does Imperial law, for that matter, but Imperial law doesn’t get quite as…worked up on the subject as they do."
Only Villains Do That, by the same author, has a similar reference - the protagonist receives a "starter bundle" of spells, one of which is Enamour. He's pretty skeeved that one of his few starter spells is a rape spell.
Only time I’ve seen an ethical love potion plot was a cute little comic featuring a couple looking to spice things up due to mutual boredom. They split a love potion, but neither changed their behavior. Both remained bored together, but with slight, visible smiles.
Honestly, one of the most scientifically plausible "love potions" we might actually be able to make someday would something that long term couples might actually be really interested in. You know that initial early head-over-heels "chemical love" that happens right at the start of a relationship? In principle that could be duplicated artificially. That would be something.
Still illegal, as the person will feel a romantic love towards the environment. Some people who've done this little experiment have been caught doing unspeakable acts to forests and groves. And for some reason, fences.
Maybe still a little questionable? Like if you honestly convince someone that they are supernaturally compelled to be in love with you, that might be a bit manipulative