AN: This was one of the many endings I thought of, but eventually moved on from for Bad Faith. This would be an AU where Lily had gone out to get some diapers or something and hadn't been there to save Harry with her love.
Sirius and Desari sighed and glanced out over the wreckage left after the war. James and his young son were dead. Lily was forced to marry Snape to keep her life. Peter had turned out to be a death eater. Fabian and Gideon Prewett had been killed protecting Remus. Remus was on the run. Lucius had betrayed his sister. Regalus had betrayed his brother. Albus Dumbledore lie dead in a shallow grave somewhere in the forbidden forest. The Order of the Phoenix was broken. Voldemort had won the war.
"Sirius, we're probably going to die." Dez whispered, leaning her head on her best friend's shoulder.
"I won't let that happen, Dez. I promised Remus that I would keep you safe, no matter what." Sirius whispered back, wrapping an arm around the terrified girl.
"He-who-must-not-be-named declared that purebloods would only be spared if they produced a pureblood heir in the next five years." Desari whimpered. "You and I stood against him. At best we'll be sold off to the highest buyer as breeders."
"I won't let that happen, Dez." Sirius insisted.
"It's too late to run." Desari shrugged. "It's our only choice."
"No, it's not." Sirius sighed. "Technically, I can still claim your hand in marriage. You were promised to me, a pureblood, and I can call on that."
"We would still be expected to produce an heir. And you're still gay, sweety." Dez rolled her eyes. "And, I'm definitely not sleeping with you."
"It would buy some time at least." Sirius frowned, disgusted. "And as two purebloods of Ancient Houses, we could claim Remus as a pet."
"Remus isn't a pet. He's my husband." I growled, glaring out at my surroundings. "He's my heart, my love, my soulmate."
"I know Dezzie, but you're starting to get crazy from being away too long, and I'm sure he is too. You two need to be together, and this is the only way." Sirius turned Desari around to look at her. "You and Remus could produce an heir. I would claim it easily. He's my brother, you'll be my wife. It would be just as much of my kid as Harry was."
"What if the kid turned out to be a werewolf? How would you explain that away?" She glared, turning to her best friend.
"The three of us can do anything. By the time the kid's grown, you'll be able to cure it." Sirius said, leaning on the railing. "I believe in you."
"Sirius… I can't–" Sirius put a finger over her lips.
Sirius dropped down to one knee and pulled a intricate silver band from his pocket. Tears began to flow down Desari's face as she realized that Sirius must have been carrying it for Fabian. "Don't cry Dezzie. He would have wanted this." Sirius whispered, closing his eyes for a moment against the grief of his loss.
When both of them had regained their composure, Sirius gently took Desari's hand. "Desari Vega Malfoy, will you do me the honor of joining me in a marriage of convenience?"
Desari sighed "Sirius Orion Black, you know I will. As long as you promise to let me help you get through this loss."
Sirius laughed and slid the ring onto Dez's finger. "Of course, my dear." Sirius grinned, tapping the ring with his wand so it would shrink to fit her.
"I'm thinking a summer wedding. You would look terrible in fall colors." Sirius said, as flamboyantly as he could.
Dez rolled her eyes. "And here I was, thinking I was a winter." The two of them laughed and went inside to wait for Remus's floo.