If you're into Harry Potter and like Snape, please read my fanfic, Heart of a Slytherin (Dark Hearts Series, Book 1)! :)
Lysandra Blackwell is ordered by Dumbledore to become Severus Snape's spying partner, and they become unlikely friends. After the Dark Lord falls, peace resumes, but there are still Death Eaters on the loose, seeking revenge. Chaos resumes; the former spies must play the largest part in reestablishing order in their world. What happens when their hearts begin a very dangerous game?
Severus and Lysandra had two children. Toward the end of their time at Hogwarts, following the arrival of a new student, suspicious things are happening and an old friend has become elusive and hostile. Severus' family is once again in danger, but this time the threat is much closer to home than any of them realized.
And The Snake and the Lioness :)
After Voldemort falls, the Order remains to fight the many Death Eaters that avoided Azkaban. Due to the drop in numbers from the war, inbreeding among pure-bloods, the Ministry passes a marriage law. Severus Snape is forced to marry returning seventh year Ceridwen Sheridan to keep her safe from the Death Eaters. AU in that Snape and most of the Order are alive.