Family from another world

15 years before, Stoick had a one night stand with a mysterious woman named Valka, who disappeared soon after. Now, years later, he's married to Valhallarama with their 8 year old son Hiccup Horrendous Haddock III. All is normal (well as normal as things could get on Berk) until reports of people riding dragons were all over the archipelago. Now, suddenly, not only does Stoick have to take care of his tribe but now he has to deal with a dragon riding ex lover and two illegitimate and rebellious teens, whom his youngest along with many of the other children has taken a shine to...what's a man to do? Inspired by wickedcriminals tumbler au