Bellatrix Black married Rodolphus Lestrange because it was a sensible pureblood partnership, and they consummated the marriage for the sake of formality, a wham-bam-thankyouma'am deal. Of course, she knows all about his liaisons with other men, and she doesn't care; she has Voldemort and that's all that matters to her. Unfortunately for her, the Dark Lord is not a physical being, seemingly oblivious to her advances. A girl's got needs, and Bella tries to fill hers by taking her pick of the male recruits. Most are satisfactory lays, and some are terrible. By 1978, Bella just wants one shag like the ones she hears her sister Narcissa having with Lucius, but when it comes to her man, Narcissa doesn't share.

Severus Snape is absolutely not her type. He's ugly, he's bitter, he's only eighteen, he's awkward to the point of social retardation -as evidenced by the fact that, at the induction party Lucius threw for him, he's standing in a corner glowering at everyone-, and Bella can tell he hasn't gotten so much as a pity-handjob in his life. But then Lucius mentions to Bella that he's seen Snape naked, and adds lightly, "I'm pretty sure he's part centaur." Hmm, Bella thinks, looking at Snape again. Hung like a hippogriff, but all pink and virginal? She can't resist. The mighty huntress stalks her prey, hoping to lull him into a sense of comfort... Before she realizes that this Snape kid is smarter than she gave him credit for and knows exactly why she's talking to him.

On Severus's end: He can see that Bellatrix is beautiful, and he's well aware of her reputation. The stories he heard in the Slytherin common room... But he's not stupid; he knows she's here to pity-fuck him, and if that's what she wants, well, her wish is his command. He can't think of a better or faster way to work his way up the Death Eater ranks than to satisfy the Dark Lord's most favored servant. He smirks to himself as she leads him into the nearest bedroom and wastes no time bossing him around, and his smirk broadens when he drops his pants and sees her expression.

Bella, for her part, isn't disappointed: The boy might be a virgin, but she's seen enough cocks to know what's average, what's small, and what's thin. Snape is none of the above, just as Lucius said. Responsive, too, but she isn't exactly surprised by that. His first time isn't exactly the screamingly-orgasmic roll in the hay Bella's looking for, but with a little practice, he'll give her plenty. He's like a puppy in his willingness to perform; she gets off on that, just a bit. Not to mention, by that time she'll have him eating out of her hands.

Yeah right, Severus snorts inwardly when Bella tells him that last part. For someone who just wants a newly-deflowered, glorified fuck toy, she's getting awfully clingy. Still, he can't say he's not looking forward to shagging her again; Bellatrix Lestrange is, in all areas of her life, a woman who knows what she's doing, and he can admire that. Use me. I'll get mine, she'll get hers; there's no way either of us can lose.

Sure enough, it only takes a few more tries for Bella to get her bed-shaking orgasm out of Snape. He's a fast learner, and it doesn't take long for him to give Bella orgasms that make her soak the sheets through each time they shag. She never falls in love with Snape, but she becomes a little -how shall we say?- possessive of him. His reputation as a great lay carries through all of the Death Eater circles, and soon he's off with the (admittedly few) other female recruits, satisfying their needs. Bella would be lying if she said that didn't rub her all the wrong ways. I made him! She thinks angrily as she watches her creation disappear into a dark corner with a new girl, freshly Marked that night. The puppy-like willingness to perform that used to turn her on so much now inspires an insane jealousy in her. The Dark Lord would not treat me this way, she is convinced, but still he rejects her advances.

This affair goes on for three years: Bella gets lays that not only turn her legs to jelly, but the house-elves wondering how such a scrawny kid can bring those kind of noises from the mistress. Snape climbs the ranks of the Death Eaters, eventually being asked by the Dark Lord himself to apply for a job at Hogwarts School of Witchcraft and Wizardry as a cover to spy on Dumbledore. All goes well for both of them... Well, there is that one time Rodolphus, jealous of his wife being treated to ten inches so often, tries to seduce Snape, only for Snape to stick the naked Rodolphus to the ceiling with a Semi-Permanent Sticking Charm, and walk away, saying "It doesn't point that way".

Not long after, Snape hears the prophecy that will change his life.

He begs the Dark Lord to spare Lily Potter -the only woman; nay, only person he's ever loved- and gets what he later realizes was a grudging, dismissive promise. Bellatrix hears about it and, at their next private rendezvous, reads him the riot act.

"What can you possibly want her for?" She sneers at him. "You have me!"

"You're married," Severus says. "And don't tell me you're in love with me; I don't believe it, either."

"Love you?!" Bella shrieks. "Of course I don't love you, you idiot. I'm fucking you because my husband isn't up to the task."

"Tell me something I don't know," Severus mutters. Like whether or not we're going to have sex, he thinks angrily. If they don't, well, too bad so sad, but he's ready to be shot of her.

"Is that what you want to save that Mudblood for, Severus? Do you think she'll fall in love with you if that blood traitor husband of hers and their hellspawn are killed?" Bella mocks.

Severus feels his temper starting to rise, but says nothing. His silence speaks for him.

Bella gapes at him for a bit, then shakes her head, sneering. "You're such a child. You believe that love conquers all. There is no love, Severus. There is only power, and those too weak to seek it." When his silence continues, Bella goads him again. "But you've been in Dumbledore's pocket for the last few months, haven't you? I suppose the old fool's ideas of love are infecting you, too. Maybe you should turn spy for his little Order of the Phoenix treehouse club-"

"Maybe I will!" Severus roars, leaping to his feet. He is surprised to see Bella back away from him, as though she's afraid he'll hit her. Oh, he won't; she's not worth the energy it would take him to hurt her. He realizes, with a strong pang of remorse, that that's something Tobias would have said, and he resolves that if this all pans out...

"Weak," Bella sneers, regaining her composure and heading for the door. "Pathetic." She's almost reached the door when she turns around to face Snape one last time. "Coward." And she leaves, slamming the door so hard that she leaves cracks in the ceiling.

Never in his life did Severus Snape ever raise a hand in violence towards a woman, nor did he ever want to. But, he thought as he repaired his damaged ceiling through magic, if he ever could have beat the living hell out of a woman, it would have been Bellatrix Lestrange, right at that moment.

But the thing about moments? They don't last.

Lily was killed along with James, the Dark Lord fell, and whenever Severus thought of Bellatrix Lestrange after that day, he felt a sort of pity for her. Why should she believe in love, he realized, when her husband was open about his homosexuality right in front of her, when the Dark Lord rejected all of her advances, and when her family had put blood purity above all else? She could think him, Severus Snape, a weak, pathetic coward until her dying breath (and for the record, she did); what did it matter to him, ultimately?

Because he knew, in whatever blackened, shriveled heart he had, that Lily had loved him. Not the same way he loved her, but she had. And there was no one to blame for her turning away from him or her death besides himself. As long as he knew both of those things were true, he also knew that love was a real thing, and worth dying for. And if Bellatrix never trusted him again? He didn't care. Not being trusted was nothing new to him.