I had my suspicions from the current chapter that the guy FL was with when they were kids was Roxanne all along and they were somehow switched- I had to go through the spoilers to check and yup it's correct! The one FL was with when they were kids was actually the ML. According to the spoilers, someone (? empress) used black magic to switch the appearances of the ML and demios (demios would go crazy and mad bc of the curse given by their goddess for being an illegitimate child etc. and the empress maybe thinking he's her real son tried to protect him idk). Spoilers still lacked information and there's a lot of plot holes here and there as the questions about who is who's true mate and what not but that's the gist of it basically.