It explains in the original book that they had an arranged marriage but ended up falling in love anyway but with the new chapter it seems like Alec developed feelings for MC before he was supposed to develop them for Lilly. The MC even tried to pair them together and neither of them were interested. That and Lilly knows that they are in a relationship and doesn’t seem to care since it was an arranged marriage. Someone told me at one point that it does say in the manga that it wasn’t really a love potion and just like an enhancer or something but it requires the person to already have feelings for someone. Alec even says it himself that he’s “always loved” Loneal which we know now was the MC in Loneal’s body. I felt the same way thinking that he was taking advantage of someone under a spell but it seems like that’s not the case
It's his mindset, his mindset of cheating being bad but go and breaks his moral by still cheating
It's not the love potion( I mean it already looked liked he wasn't affected by the potion that's why i added quotations to "under") the thing I have a problem with is the MC thinking about morals, his constant thinking about his "childhood" friend, and that it's wrong to do this and that because he has a fiance/ because he's for the og MC
Like why keep spam thinking about morals and cheating not good while they're holding eachother just cause he thinks the ML was "under" a love potion
He can refuse the advances even if he really was under the influence of the love potion
But he didn't and that's why whatever is in the spoilers it still doesn't change the fact that from the start he's still a cheater

I really can't get over the fact that they're cheating, like i know it's an arranged marriage but that doesn't excuse loneal taking advantage of the "under" a love potion prince. The Prince is the one who's supposedly under a love potion not loneal so why is he indulging in it
And it's even more irritating because when they go and do it, he thinks of his childhood friend feeling all guilty and proceeds to let his childhood friend's fiance eat his ahh
Istg I've seen another one of this characters in a different story and it pmo like I know you want the og to get together because you love them as a couple but why are you home wrecking if you want them to get together atleast the other story I saw no one was cheating and the mc was just admiring and pushing them close together but this one just straights up
"I want u to marry my MC but please eat my ahhh too"