It's essentially the same as the English one. If you heard from others that Eirika and Ephraim married, you were BSed (although it might not be the others' fault).
After the war, Ephraim and Eirika returned to the royal capital where they spent many busy days working to restore the entire continent. Their work revitalised those who had lost hope. Eventually Ephraim became a king who received huge support from his people, and Eirika supported her brother by his side for a long time.