Why not both?

You knead Karina's breasts, your attentions causing them to swell slowly as her arousal mounts. When their growth seems to slow, you add your mouth to the mix, teasing her nipple with your lips and teeth until her tits are so large you can't see her face. You give her left nipple one last soft bite and release her, leaning back to rest on your knees, staring at her supine body. She pushes herself up as well, facing you with her legs splayed in front of herself, massive boobs almost resting on her thighs.

She catches her breath, chest heaving and deflating slightly as she collects herself a bit. Her purple eyes lock on yours and she bites her lip. "Would you fuck me now, sir? Please, I'm so horny, please fuck me."

You don't answer her. Slightly unsteady, hard cock pointing straight out in front of you, you rise to your feet and sit on the futon, slouching heavily and stretching your arms across the back. You're in a perfect position to make eye contact with Karina with your dick in both of your lines of sight. Her eyes can't seem to look away.

"Please, sir, I need it so bad. I'm a horny little..." She hesitates slightly. "I-I'm a horny little slut, sir, and I just want you to take me and-"

You cut her off with a hand, then gesture to your cock. She crawls over and takes you in her mouth again, bringing you deep and holding you for longer and longer stretches of time. She looks up at you as often as she can, that dominant expression still peeking out from somewhere but mostly hidden, eye makeup mostly immaculate save for some smudging near the corners. She's actually quite good at this, and you let her go to town on your cock for a nice long time.

Finally, you place a hand on her cheek and pull her attention away from your cock. You wait a heartbeat, then ask, "Would you rather fuck me now but be unable to have sex with anyone else ever again, or not fuck me now and forever lust after me."

She gasps in arousal, the delicious look of decision coming over her face again, then stammers out "I-I'd r-rather f-fuck you n-now."

Moving quickly, Karina stands up and gets on her knees on the couch, straddling you. She takes a breath and lines herself up, then lowers herself onto your cock. The time for subtlety, if you ever had it, is over. As she begins bouncing up and down, slowly gaining speed, you start to thrust up to match her. One of your hands finds her tit and begins to maul it. She leans down for a passionate kiss, then pulls back to moan in pleasure. The rhythmic sound of sex fills the apartment. As you continue, you feel the wetness of her pussy continue to grow, even running down your balls and thigh and smelling slightly sweet and musky.

She reaches orgasm and cries out in ecstasy. As she does so, a noticeable amount of volume leaves her tits. They're still large, but not as **** as they were before. Her tempo doesn't let up, and you feel that you're not too far behind her. You bring one of your hands to her hip, placing pressure to slow her pace a bit, your other hand draping over the back of the futon to give you some leverage. Taking her cues from you, Karina matches your movements with her own, slowing things down slightly, trading speed for technique, letting each thrust and bounce hang for a moment at the apex. She starts flexing the muscles in her pussy on each downstroke, making her feel tight around your cock when it matters most.

She's clearly getting tired now, both of you are, and you can see a shake in her leg muscles as she tries to keep bouncing until you cum. At a certain point, she leans forward and plants both hands on the couch on either side of your head to support herself. From here, you can look deep into each other's eyes, and in hers you see that deep fire of suppressed dominance, the unquenchable arousal, and the absolute attraction she feels towards you.

You wonder what she sees in your eyes.

With a final upward thrust, you cum harder than you have in a long time. As you do so, Karina's legs finally give out from under her, causing her sit down hard on your lap and burying you deep inside her. You can feel your heartbeat trying to burst out of your chest. Your cock pumps five, maybe six times inside her before you drop back to your seat, toes curling and uncurling with each pulse. A breath you didn't know you were holding escapes your lips.

"Fuck."

Karina has collapsed against your chest, breathing hard as well, a light sheen of sweat on her chest and back. "Mmm.... was I good, sir?"

"Very good, Karina." You pet her head gently. "Very good."

You help yourself to some water in her kitchen. You assume Karina's dressing herself in the living room, though you honestly have other things on your mind. What you've been handed here is an incredible opportunity and a potential catastrophe. A double-edged sword.

You try and remember all of the options you've given. There weren't any immediate red flags that might backfire if left unchecked, besides Karina potentailly needing new bras. Her eyes could be explained away as contacts. She might never have sex with anyone but you again, but you figured that could be reversed if it had to be.

It might be a good idea to come up with a list of questions less likely to cause problems. And memorize it.

There's a cloud hanging over your thoughts, not quite a stormcloud but definitely casting shade: the look. The expression Karina had when you gave her a difficult decision. That suspended moment of fear, arousal, and uncertainty had felt so good. You want to feel it again soon, as soon as possible. It's a need.

The feeling of water overflowing the glass and pouring over your hand snaps you back to the present. You shut off the sink and drink thirstily, gulping it down and going back for more. After the third glass, you feel pretty satiated. Leaving it in the sink, you shuffle back into the living area and pick up your clothes, putting on your pants and shirt and brushing off a few scraps of lint from the carpet. Karina is nowhere to be seen, but you hear a faucet running in the bathroom.

A few minutes later, she steps out into the hallway. Her lipstick has been removed, the smudged eye makeup reset. Her white t-shirt hangs loosely over dark jeans, the outline of her bra distinctly visible through the thin fabric. She seems nervous, not on edge but definitely anticpating something, looking at you with furtive glances, looking everywhere but your eyes. You're starting to recoginize some of her body language.

"So... um... so you, I mean we, I-" she begins, then trails off.

"It's okay," you say. "That was a lot."

"Yeah. I mean, yes, sir. That was a lot."

"You made a lot of choices, too. How are you feeling?"

She bites her lip a little as she thinks. "I did, but there weren't a lot of options. I guess I picked which ones I thought would be the best choice." She looks you in the eye. "I had to give up a lot, too. To you, I mean."

You take that in. She picked the 'better' choice, but that didn't mean she had to like it. And it's true, you did end up taking a lot of power over her. You might be able to give some of it back if you wanted to. Or you could take even more, take away her ability to understand what she no longer had, entirely strip her of agency.

Or you could leave things exactly as they are right now.