May I suggest: Hiccup getting pregnant during RTTE (could be t4t Hicstrid, post one night stand, noncon result, or otherwise) and doing a good job at hiding it from the hunter's for the longest time.
Then, one day, he gets captured by Viggo and it comes out. Maybe he says it in a panic because the hunter's are roughing him up or threatening a beating and he doesn't want the baby to get hurt. Maybe Viggo notices the baggy tunic just barely concealing a, fairly obvious without clothes, baby bump.
How do we think Viggo would react? Would he be jealous? See it as another thing to use against Hiccup to try and get what he wants? Would he freak out or be mad, because now he's realizing that for the past few months Hiccup had been continuing to foil his plans all while dealing with morning sickness and cravings?
Also, maybe, Viggo touching the bump. Morbid curiosity, an excuse to touch Hiccup, the reason doesn't really matter. But the baby senses Hiccup's distress and starts moving around. Kicking properly for the first time, right against Viggo's palm.
Excuse me while I clutch my chest and faint from the sheer evil of that last paragraph.
Like, holy shit, my friend! This is evil. This is straight up evil.
So, naturally, I am absolutely thriving off of it.
*me vibrating at the speed of sound* Don’t write a fic for it, don’t write a fic for it, don’t—fuck. *gets out my writing ideas list again*
I like the idea of t4t Hiccstrid in this! I want Hiccup to feel loved and to love this baby in return. In my opinion, that just makes the unwanted touching from Viggo so much worse.
And to think the baby kicks for the first time at feeling Viggo’s hand? I’m going absolutely feral over that! That was something Hiccup wanted to share with Astrid and Toothless first, and then his friends. (I like the idea of Hiccup sharing that sort of thing with both Toothless and Astrid simultaneously, so no one has to be jealous about who got to feel the baby kick first.)
But Viggo feels it first.
And this absolutely destroys Hiccup inside. Top tier angst. All the angst.
I feel like this is definitely a “write and find out” situation with Viggo and how he reacts to all this, because at the moment, I’m honestly not sure. Hiccup and the baby will be physically safe, I think, even though it’s Viggo they’re dealing with. But emotionally? Scars to last a lifetime.
This was so utterly fantastic! Hope I eventually get to writing this as a fic!