Yeah, the second prince only had himself to blame. It’s revealed that the Remilia’s adopted brother also eat the cookies that had the seduction magic, but it had zero influence on him because he was obsessed with the Remilia. He only went along with the prince because he believed that if Remilia ended up broken and devasted, he could sweep in and save her (classic Yandere). He makes it clear that it wasn’t actually manipulation magic but that you already had to be attracted to Pina for the magic to have an effect. The prince liked Pina and deserved everything he got

I genuinely feel bad the the prince actually, like he was manipulated by magic and the star maiden so he literally couldn't pursue Remi.
He was under a spell and he gets PUNISHED for it, like he genuinely loved Remi dude I wish she gave him a second chance but I see why she didn't, R.I.P my guy :(