Possibilities
"Come on, Xander. You're acting like your girlfriend's never had sex with anyone else before," Anya said, stamping her foot.
"That's because my girlfriend's never had sex with another person before! It doesn't work that way, honey. That's why they call it monogamy," Xander sighed, straining to make himself understood.
Anya pfftted. "Please. You don't think I've seen enough relationships go asunder to know that monogamy doesn't work? Hell, it was 98% of my clientele!"
Xander waved his arms around helplessly, searching for a sentence that would counter such insane logic. Ah, the joys of relationships.
"For instance, about fifty years ago there was this woman who watched from a closet as her husband had complicated sex with two women who were taller than him and wore harem-girl outfits, which were so unauthentic anyway--remember when I told you about the Arabic couple from the fourteen hundreds? That's when I saw those veil-dresses you wanted to have remade, and then we had odd but good sex--and I turned that man, that two-women-harem-girl man into a toad, which the woman ended up taking care of till she died. And then there was this annoying fish merchant, in 1245. God, he stank. Anyway, his wife was a real bitch and she caught him screwing the next-door neighbor's wife--hoo boy, that was fun. I gave him blisters in places it is not naturally possible to have, and he begged her forgiveness every day. She never gave in, good woman that she was. Oh, and I completely forgot about the time with the goat and the scullery maid--"
"Fine," he interrupted. "Do whatever you want."
She gave him a bright smile, and came over to give him a kiss on the cheek. "Oh, Xander. You know that me having sex with another girl will increase your fantasy life by ten times, at least!" she said cheerfully before heading out the door.
"Another...girl?" he said faintly, plopping onto his couch-bed.
There was a knock at the door, and Tara startled at the sound. She was still unused to people knowing she was around. It might be Willow, she thought, brightening at the idea. She climbed from the nest of blankets and pillows she'd made on the bed to get to the door, opening it with caution.
"Hello. Let me in."
"I-uh. You're Anya, right?" Tara said, widening the door slightly.
Anya nodded as she entered, seeming to take the sliver of an opening as an invitation to enter. She looked around the room, as if inspecting it. "Your room is dark, yet inviting." She plopped down on the bed, running her hand over a felt pillow. "This will do."
"I'm sorry?" Tara said, lost.
"You are an appealing female, and I would like to copulate with you. I've discovered that there are many ways to interlock, and I most certainly want to explore them all, as long as I'm in this annoying human form," she frowned, poking her arm. "And, as you and Willow haven't made any public statements of commitment or monogamy, which is stupid anyway, I would like to copulate with you."
"Um."
"Well, that's fine. You don't have to say anything. It's common in the relationship Xander and I have that I take the dominant position, so I can apply that here and we can get on with the copulating."
Tara didn't have a chance to reply before a hard, insistent mouth was on hers. Surprised, she opened her own wider, letting an intrusive tongue in. Anya pulled her closer, causing their breasts to rub against each other. Tara felt her nipples harden, and she gasped harshly through the wanton thrusts Anya was making in her mouth.
She finally wrenched herself away, panting hard. She stumbled to the chair in the corner, rearranging her layers of sweaters and skirt, pulling into herself. She couldn't speak; she was too stunned, going over the last three minutes in her mind.
Anya simply looked at her, brushing a stray hair out of her face and straightening her wrinkled blouse. She waited a moment or two before sighing noticeably, drumming her fingers inaudibly on the comforter. Finally she let out a frustrated noise. "Are you ready now? Have you had enough time to regain your air supply? Because I would like to return to the kissing now."
"We can't," Tara said softly. "I mean--Willow--I want to be with Willow."
Anya made a face, and gave an odd sort of laugh. "Sure. I want to be with Xander. I am with Xander. But that doesn't mean I can't explore the other ways this body can function, and some of them don't include Xander. They include you, if you'd just come over here. I don't think Willow's done anything with you other than stare a little bit. I can tell, it's what I was trained for. So, consider this practice if you have to. It's just preparation for what you'll do with Willow later, okay?"
Tara shook her head. "No. This--this is crazy. I want you to leave, okay? Because this is weird, and scary, and I have a hard enough time trying to keep up with Willow and all her friends without adding--without adding you to the mix. So, please. Please go."
Anya rolled her eyes and stood. "Humans are so complicated. Its just sex." She sighed and walked to where Tara was sitting. "If you change your mind, I'll be at the coffee place down the street." She bent over and brushed her lips against Tara's in a surprisingly tender manner, causing Tara to shiver and look away. "Goodbye. Have a pleasant existence."
Tara sat there for a long time, looking around at her room, noting where it had been disturbed simply by Anya's presence. She breathed carefully, almost falling into meditation, thinking about everything that just happened.
Finally she stood, glancing at her reflection in the mirror before heading out the door. She decided she wanted some coffee.