Urgh, even after reunited, he still keeps being cold toward his fiancée for years. Does him have no one around to remind that those kind of behaviours are not okay? (his father? his close aides?) This has already surpassed being embarassed or tsundere, this is simply being an asshole. If the timeline is not skipped, I woundn't be surprised if his fiancée had already grew sick of him by now. You can't just expect someone to keep tolerating and loving you back when you treat them like shit, just because of some childhood memory a decade ago. I guess he's trying to become someone super high ranked so no one can make fun of his fiancée again, but geez, the author could have write this better.