Responses
um? Did you forget? The MC is YOUNGER than the other princess. In other words, he probably only met the MC's mother after he already had the older princess. So, in this case I don't think he qualifies as a "cheater" when he had not even met the MC's mother yet.
Why he sad? Why he sad about the other girl and even say the to mc 'did you learn about her..' he clearly sad about other girl.. and if he love mc like that why he cheat her mom?