Fellowship of the Pranksters: Step-Atto Fingon
When the kidnap fam first arrive in Aman, it quickly becomes obvious to Maedhros that it's going to be very difficult to keep his relationship with Fingon a secret. When Maedhros and Maglor took the twins, it was common knowledge that Maedhros had been married to Fingon and that Fingon had died.
The first time someone brings up Fingon in the twins' presence, Elros recognizes the name immediately, turns to Maedhros and says, "Wasn't Fingon your husband?" Luckily, he had said it in Sindarin, which nobody in the house has yet learned.
That night, Maedhros has a talk with the twins and tells them that they need to keep Fingon a secret. They ask why, and he says it's because they aren’t married yet. To be fair, that IS part of the reason.
When Fingon and Maedhros begin their secret courtship, Maglor, Elros, and Elrond tease both of them MERCILESSLY! Whenever Fingon comes to visit, the twins always pull him off to play with them. He doesn't resist all that much.
A few weeks after the Russingon wedding, Fingon is hanging out with Elros who says, "You know, it's nice to finally have a mentally stable parent"
Fingon really doesn't know what to say to that.