It takes a very long time to convince 21 that this is real, but Bulma doesn't really concern herself with whether this is reality or not. She sees a chance to be your partner, and she's going to take it come hell or high water. "Hm. So that's what happened…" 21 murmurs, "Interdimensional invaders. And you want our help fighting back against them?"
Bulma holds up a finger and raises a simple objection, "I can't fight."
You nod, "We know. The reason we chose you two is because you have incredible minds for technology and science. We'd like your assistance with breaking the mystery behind this CPU behind us. It's far too advanced for us to figure out alone."
Lala smiles and wraps her arm over your shoulders, "And in return, you get to spend time with hubby!"
Bulma frowns, "Damn it, guess I should have expected a hunk like you to have a few wives already."
"It's fine!" you insist, "Give it a few days and see if it's something you're interested in."
You know that Bulma is interested, the entire point behind summoning these versions is that they're going to immediately fall in love with you. But you still find yourself trying to be reasonable with them if they have reservations about the size of your increasingly silly harem. It's egotistical to assume, but these two are going to end up in the harem eventually no matter what you do.
"Oh, I don't mind! I'm more than pretty enough to get the attention of a man!" Bulma boasts, intentionally squeezing her arms together to try and emphasise her chest. "Soon, you won't be able to keep your hands off of me."
21 adjusts her glasses and coughs to try and draw attention back to the topic at hand, "Do you mind? I believe we have something else to focus on at the moment."
Mitsuru smiles, "So that means you'll agree to give us a hand?"
"I see no reason not to. If this device is of any interest, I'll pledge further assistance in return for information sharing on what we discover."
"Alright, just be careful with this stuff. These guys are way more advanced than any other organisation in the multiverse. We don't need anyone else ill-intentioned getting their grubby hands on these computer parts."
"I'll get back to you later, handsome!" Bulma giggles. She gathers around the workbench with Lala, 21 and Mitsuru to study what she's managed to do so far. Mitsuru had put together a rough schematic of what the device looks like on the inside. Bulma puts her amazing mechanical skills to use right away and drafts a second revision that makes things more precise and cleaner. You step back and sit down on the old couch to observe. You'll only get in the way if you try to offer anything to them.
It turns out that the combined brain power of the four of them is enough to crack the code in record time. Mitsuru is beside herself as 21 and Bulma easily blow past the problem that had stumped her mere minutes earlier. The CPU is dismantled bit by bit, with each component and material carefully studied using the analysis tools that Mitsuru has purchased with her toy line money. At first you thought that they wouldn't be a good team, but in reality, they're working so quickly that all four of them are taking on different jobs at the same time without even saying anything to each other.
You feel like a ghost. Bulma's flirtatious attitude dashed to the wind as her love of engineering and computing overrides her need to hit on the first handsome guy she sees. What kind of medium do you exist as in her world? A manga? TV show? All of the above? Or perhaps Mitsuru found a universe where she is simply very compatible with you. There's plenty of time to think about these things as they begin to chatter happily within the lab and share their findings.
"This alloy is superconductive," 21 explains to Lala, "It generates no electrical resistance at all, something we can only usually observe at freezing temperatures."
"Wow! That kind of thing is still in the early stages of theoretical discussion back home."
Meanwhile, Bulma has already put together a complete copy of the motherboard's plan and projected it up onto Mitsuru's computer monitor. "Hm. It looks like we won't be able to produce copies of these after all," Mitsuru concludes, "We'll have to treat the ones we have with care."
"How many of them do you have?" Bulma asks.
"We retrieved ten. I'm keeping some of them as spares in case the main computer destroys it."
"That should last you for a good while. Is it true that you really can't make any more of these? I'd love to take one home for myself."
Mitsuru adjusts her glasses, "I'm afraid not. None of these compounds can be made under conditions found here on Earth. They must have used their reach as dimensional travellers to find natural sources, or extreme environments where they could synthesise them." This is all way above your paygrade – even when you're getting paid tens of millions of dollars in dirty toy money. Giving yourself a workout in the gym while they work seems more productive, so you leave them to it and run your drills.
Chun-Li has been working you like a dog to make sure that your conditioning is up to snuff. Things are only going to get harder from here on out, and you'll need a superhuman level of capability to get any stronger. Just as you're about to finish up, Bulma walks through the door and leans against the wall. She lets out a long whistle as you grab your towel and dry your head from the sweat that has accumulated.
"Finished already?" you ask.
"That's right. Your little friend was really happy with the work we did. She's already making plans to hook it up to your system."
It's impossible to ignore the way that Bulma is eye-fucking you as you towel down; "Thanks. I know it's weird to be dragged here suddenly and asked to help someone you don't even know."
Bulma insists, "I'm happy to! The technology that she's researching is incredible. The prospect of getting one of those computers for myself is payment alone. She also said that my own world might be under threat. And I'm not going to let those muscle-headed morons take all the credit for themselves."
The prospect of getting to hook up with you is probably weighing into that decision as well. "Did you see us on TV back home? That's how most of our allies know us."
Bulma smiles, "Oh, you already know? Getting to see you in the flesh is a real treat. How many girls do you have on the go right now? I'd bet good money that they can't keep their hands off of you."
"…Nine."
"Only nine?" she gasps.
"Hey, having two partners here is considered weird! Nine is something special." Your mind flips back to when Chun-Li implied you'll soon have hundreds of them. Bulma walks up to you and gets a closer look, rounding your body and really inspecting your form from every angle.
"Hm. You're not as built as you were in the TV series," she observes, "Not that it's a realistic depiction of a human male in the first place." That's a lot coming from a woman who exists in the world of Dragon Ball Z – even the humans over there can do feats of strength and agility that are simply impossible to the likes of you. They're all hulking mountains of men, far beyond what you can realistically achieve without hitting some steroids. Which, in this case, would be a terrible idea. The last thing you want is to injure one of your muscles in the middle of a fight.
Bulma tries to be on the bright side, "Tenth place is better than I expected!"
"Oh, so you're on board – just like that?"
She smirks, "What do you think? I've been fantasising about this for too long to let the chance pass me by! I'm sure your other girls are great too. And didn't you summon me because you want to add me to your collection?"
"That's a straightforward way of putting it."
Bulma places her hands on your back, "I'm an honest woman! I don't like screwing around. We both know what this is really about, so why wait?"
"Heh. Forward people like you really make my life easier…"
"I need to find a good man. I'm not getting any younger over here… not unless I find them again."
"Find what?"
She gives you a terse smile, "Nothing! Just thinking to myself." The nervous laugh that follows is completely unconvincing. You reach down to grab your stuff and change back into your casual clothes.
"What is 21 doing?"
Bulma frowns, "She's too deep in her work – that girl doesn't know when to quit! Her loss, that means I just get you allll to myself." The hand trailing down your chest makes it clear that Bulma wants a more sexual encounter than you were planning on. But you don't see any reason to reject her now that the major work is done. You respond in kind and wrap one of your arms around her waist, causing her cheeks to flush as the intensity of the situation is kicked up another notch.
"You must feel like the luckiest woman in the universe – out of all of them, you were the one who ended up here." Leaning into her neck, you place a kiss beneath her jawline. Bulma's grip on your back and chest tightens as a rush of arousal runs through her body. "I like to treat all of my women well, you know? So if there's anything you'd like me to do as payment for your hard work…"
It's corny, but that's exactly what Bulma wants out of a man. You have to appreciate the finely tuned curvature of her hips and ass. She isn't boasting the bra-busting proportions of Akeno or Rias, but you just know that she's going to look amazing when you rip this red dress off of her.
"Hmm," she purrs, "What kind of options are you offering me?"
"You can join me in the shower, or we can go downstairs and use one of the private rooms."
It's a genuinely difficult decision for Bulma to make. She bites her bottom lip and wavers from side to side as she tries to settle on one of the two proposals. You stink – you don't know if Bulma has a thing for someone who smells like a wet dog. She does hang around with a bunch of overly muscular dudes, maybe she is. You decide to take matters into your own hands and give her a push.
"Let's shower together. I need to clean off, so why not get dirty again first?"
"How many times have you used that line?" Bulma snickers.
"Only once, actually." You take her hand and lead her to the back door. Another benefit of heading through into the shower room is that you don't need to go through the lab, where Mitsuru will surely deduce that you're going to sleep with Bulma and crack jokes about it. That would be a big mood killer. Bulma sits back and enjoys watching you strip off your clothes – but you get the feeling that you aren't as impressive as someone like Yamcha. You've filled out a lot thanks to the exercise, but there's still a fair amount of fat covering your muscles; but some women prefer that kind of body.
Bulma blinks the stars out of her eyes and remembers that she's meant to be joining you. She approaches and turns around, showing the long zipper that runs down the back of her slim dress. You do the courteous thing and unzip it for her, after which she shimmies the fabric down from over her shoulders. Her bare back and shoulders are well-defined. She steps away and undoes her own bra strap. With everything unhooked – it takes one strong yank from her to bundle the entire collection around her feet.
A pair of thigh riding panties are the only thing left, and they do an amazing job of lifting her perfectly shaped butt. You can stop your hand from reaching down and sneaking a quick squeeze, to which Bulma scoffs and slaps you on the chest. "Patience!" she admonishes you, the smile on her face betrays how much fun she's really having. She kicks off her heels and bends over to remove her panties, exposing her clean-shaven slit and asshole. Bulma is keeping things trimmed, it seems.
You're already erect from the display of Bulma stripping down, but for the time being your primary concern is making sure she's comfortable. She places her hand into yours and allows herself to be pulled towards one of the booths, the frosted glass providing a questionable level of privacy. You close the door behind you while Bulma fiddles with the shower and sets it running. A brief surge of cold water splashes over you. Bulma squeals and wraps her arms around you in a hopeless attempt to keep herself warm.
You whisper into her ear, "Which part would you like to clean up first?"
Bulma giggles, "Allow me." She sinks down to her knees and is presented with the full length of your shaft. Bulma's look of approval is yet another ego boost, but you aren't going to take this for granted. She wraps her hand around it and angles it downwards, opening her mouth and wiggling her tongue like a little tease.
Blowjob it is.