When they went to live with their grandparents the triplets felt very hopeful about the future. Their parents' warnings even looked entirely unwarranted after a while.
It was after their first "mixer" with "people of their age" that they noticed anything amiss. The questions didn't sound that bad at first, typical parental figure inquiring about romantic prospects. But the questions got insisting and the parties more frequent. The young Daliath women looked less friendly and more "looking for an opening to exploit", so did the girls' relatives.
For a while, Felix (or Feliaris in this world) held to the hope. He gave his grandparents the benefit of doubt. Then one night they are at a party with some Daliath from Parjen. Full-augmented Daliath, unlike the local norm of partial augmented like his family. Felix started a conversation with a (very) tall dark-skinned young woman, his age and a fashion model.
Their grandparents almost stopped the conversation by force. It must have been coordinated, some people distracted her and another set distracted him. Felix joined his brothers in not-attending the kind of event.
Then the grandparents, got wind of some rumors and confronted the triplets about it. Separately, so they couldn't coordinate. Luckily, Fernando predicted the possibility, and they collectively deflected any questions. It was suspicious, but it meant their grandparents knew nothing besides that there was a boy named "Katur".
Their grandparents changed tactics. Of course, they did.