
Well he's supposed to be the next Emperor and Irene and MC are both I guess you could say "fighting" for the title empress but being a Regina makes them both capable of being at least a queen and the only reason the prince was rude to MC in the beginning was because how her father didn't support him as the heir but now that the prince spent time with mc I think he has a thing for her now maybe

I also thought that he a cheater too but it's seem...he,who doesn't good eyes unlike 7th prince probably thinks of Irene as a person who could help him to run the country which why both him and Irene become a lover. And Irene pretty much used him to climb her family to be a royalty. ╮( ̄▽ ̄)╭
My opinion ah.

If that were the case then that wouldn't explain why the prince is constantly helping Charti in the later chapters and not lending a hand to Irene past that one scene during the ball. As I've said, we're reading things in Charti's eyes. Her doubts reflect on our opinion on the prince even if they aren't right. It gets clearer as we go on. But despite all that, Charti's not romantically interested in either of the princes. She's also not in a love triangle with Cailanden, the fifth prince. She only wants a platonic relationship despite knowing full well the other might be interested in her that way lol.

Why would he doesn't need to help Charti? (⊙…⊙ ) In my eyes, he kinda innocent unlike other ML in other mangas similar to this. (▰˘◡˘▰) So, I assumed he will go for justice than defending his lover. Moreover, his brother's reputation is at stake(is it correct word? ) at that time. And what I mean for my previous comment is both of them became lover not because of love or smthng like that but one thought she could help him while other one used him to climb as empress. (づ ̄ ³ ̄)づ Yes, we read it in MC perspective but her opinions are not only based on her perspective but in rumors that she heard too which why I thought he looks cheater but it's seem not because it's not love for them to be a lover but other reasons.
Did my words understandable? (⌒▽⌒||)
Does the Prince actually love Irene? because it says that their lovers. so why is he talking to the MC then, doesn't that make him a cheater?? I know that Irene's evil and that he should dump her but it seems like they're actually together??