"If this keeps up much longer, I'm going to write a thesis on it."
Chichi looked up from her tea and raised an eyebrow at her friend. "Bulma-san, you work with computers and mechanical things. You're an inventor. You are not a biologist."
Bulma glared into her mug. "I think the term in this case would be xenobiologist, but I'm still tempted to do something to keep me from wringing their necks!"
The topic of conversation was, as usually was the case when Chichi and Bulma got together, Goku and Vegeta (the other general topic of conversation was Trunks and Goten, who were currently climbing to the top of the house and jumping off the roof to see how hard they could hit the ground. Thankfully Saiya-jin were very hardy and the ground was more at risk than the kids) and theorizing on why they were almost constantly at one another's throats.
"Even when they're getting along, I swear to Dende they're trying to kill each other," Bulma complained. "I'm honestly starting to think that it's some twisted, complex mating ritual and we're both going to be left for someone of their own species."
Chichi snickered softly and shook her head. "I don't think that would ever happen, Bulma-san," she said reassuringly. "You've known Goku for longer than I have, and if I know even one thing about that man it's that once he's given you a promise he won't ever break it. I mean, he promised to marry me when he was a kid and did just that when he was barely thirteen." She smiled warmly and took a sip of her tea before adding, "Besides, haven't you noticed what all of our kids call us?"
Bulma frowned thoughtfully before glancing out the window in time to see her little half-Saiya-jin hell spawn slam into the ground hard enough to leave a dent. She rolled her eyes as he dared Goten to top that if you can. Everything in her world had changed with his birth, energy that she'd previously focused solely towards inventing splitting to give equal attention to her life's work and to her small, very much nontraditional family. Hell, Vegeta wasn't even her husband, but she felt territorial in regards to him. It was the reason that Goku's attentions, violent though they may be part of the time, bothered her so much; it felt to her like someone was poaching on her territory, and it was hard to reconcile her long-time friend with the man who she sometimes saw as a romantic rival.
"I don't know what you mean, Chichi," she finally admitted after a moment. "What about the kids?"
The black-haired woman laughed. "Every time Trunks comes over to visit, I worry if he calls me anything other than okaasan because it probably means he had a rough day at school," she said, grinning a bit more as Bulma's blue eyes widened in surprise. "He also calls Goku otousan and Gohan niisan. And whenever you two come up, Goten usually refers to you as mama and papa, just like Trunks does. I swear they must think they're actually brothers who just happen to live in separate houses with one set of their parents."
"Now that you've mentioned it, I have to admit that Goten has called me that a few times at Capsule Corp," Bulma said, her voice calming as she pondered the implications. "Do you think the kids really believe we're all just one extended family unit?"
"Hell yes," Chichi replied emphatically. "As for what my husband and your partner get up to, I tend to just try and remember that they are a completely different species than we are. What's normal for human beings like us might be strange for them on an instinctive level."
"Yeah, well," the blue-haired woman replied, "I still think the whole cycle of fighting til they almost kill one another then provide backup in the next major fight with someone trying to destroy the world is a complex mating ritual."
In some way, she'd always sort of felt like Son-kun (as she still referred to Goku in her own mind and when speaking to and about him) was family in a manner of speaking. She'd hadn't exactly thought of him like a brother, not really, but as he'd gotten older he never graduated to dating material either. She'd just put him in a nebulous bubble labeled my family and left it at that.
She hadn't noticed it when Chichi and Gohan were added to that bubble, but she'd mentally categorized Vegeta into a bubble labeled my partner/mate/father of my child and adjoined that to the my family bubble with Trunks' birth. Somehow, she hadn't realized that it was the same category as Son-kun and Chichi and Gohan inhabited; she again didn't really notice when Goten was slipped into the same category.
Somewhere along the way, her idea of my family had grown to include an entire other household, and she was starting to notice that Son-kun existed on the boundary between that category and the one Vegeta existed in.
So, after the conversation with the other woman involved in the square, Bulma decided to maybe just observe and evaluate.
What she noticed was interesting, to say the least.
Vegeta and Son-kun fought. A lot. In point of fact, most of their interactions involved either actively trying to maim one another or sparring with some verbal jabs thrown in for good measure. But mixed in with that, Bulma couldn't help but notice how pleased they seemed to be during those sessions. It almost seemed as if they fought against one another to prove that they were capable of protecting one another when it came down to a life or death situation.
And dear Dende, did they watch each other's backs when those situations arose.
Bulma couldn't honestly count how many times Son-kun had carried a wounded Vegeta back home after a major battle, or how many times the situation was reversed and it was Vegeta carrying Son-kun back. And every time, they snarked and sniped at one another verbally the entire time with an air of contentment around them both.
It was obviously some Saiya-jin thing, and probably completely instinctive given that they were the only two full-blooded members of their species left and each of them had killed one of the only beings would could have explained things to them. So without some sort of guidance, Vegeta just did what felt right to him in expressing an interest in another Saiya-jin and the desire to protect that other; and it appeared that Son-kun had no problems following his elder's lead (even though her partner was only a few years older than Son-kun and sometimes acted younger).
So Bulma resisted the strong urge to write a scientific prospectus on the mating rituals of the Saiya-jin and instead watched the behavior patterns of all the aliens and half-aliens in her life. A few weeks of observation proved that Chichi was right about the younger kids; now that she was paying closer attention, she caught Goten calling her mama nearly every time he spoke to her. She noted that both boys addressed Son-kun and Vegeta with paternal titles, and neither adult Saiya-jin protested in any way. In fact, Vegeta gave equal attention to the kids during training sessions while sniping at Son-kun on nearly every topic under the sun.
What gave her a moment of pause was when Gohan had slipped and referred to Vegeta as chichioya and the elder Saiya-jin hadn't even batted an eye, only instructing him to "go check on the other brats and make sure they haven't managed to kill themselves today."
That was the thing that convinced her that the idea she'd had of maybe having a slightly nontraditional family was blown right out the window. Apparently at some point, Bulma had managed to find herself as a co-mother to three half-alien boys along with another human woman and sharing her sexual partner with another male alien. And somehow, that felt perfectly normal; or at least, more normal than only sharing parental responsibilities with one other person seemed to be.
"We're part of a polyamorous relationship," Bulma calmly informed Chichi the next time they met for drinks, this time coffee and wine at the Briefs' apartment above Capsule Corp.
"That we are," Chichi replied with a nod, watching out of the corner of her eye as the two youngest half-Saiya-jin tore past the den on their way to Vegeta's training room. "Does it bother you?"
The blue-haired woman smirked. "The only part that bothers me is why our men get to have all the fun."
Chichi stared at her husband's lover's mate for a few moments in silence before smiling wickedly back at her. "Then we should probably remedy that situation, Bulma-san."
Needless to say, Vegeta and Goku were left in charge of the kids for a few hours while the women re-evaluated their relationship status. All the Saiya-jin could do was wonder why in the hell it had taken their females so long to get with the program and fully blend their family group together.
"Eh, must be a human thing," Goku finally decided; Vegeta sneered but agreed with the assessment.
Goku wanted to stay in the house he and Chichi had started their branch of the family in; Bulma argued that it was too small and would never survive two full Saiya-jin, three male half-Saiya-jin children, and the half-Saiya-jin baby that was still a few months shy of being born. Vegeta wanted to keep the apartment that he shared with his woman and offspring above Capsule Corp; Chichi snorted and said that it was far smaller than her house even if it might be tough enough to deal with Saiya-jin mishaps. Eighteen told them that they were all idiots and should just buy an island like she and Kuririn had done; Seventeen suggested they all build a new house somewhere in the country but not in the woods, because while he enjoyed coming around and playing the "cool" uncle, he sure as hell didn't want them right next door to him.
Eventually, after nearly everyone they'd ever met had weighed in on the subject (including Piccolo's "I don't care, just don't come to me when you need someone to watch all those brats" and Mr. Satan's "I'll just buy you a nice place so long as you pay for the wedding when my baby marries your son"), the four adults came to the consensus that they would just have to build a home that would fit their needs. It took months of scouting for the perfect location and of the Saiya-jin digging a foundation by hand (and, as always, arguing about the process) and of Bulma trying to decide what materials to use, but eventually they had a post-modern house that was perfect.
There was a large master suite for the adults to use, complete with a specially-made bed large enough to comfortably hold four people who tended to sprawl everywhere in their sleep and a crib for little Bra to sleep in for the first months of her life; she'd been born only days before the construction work was finished and Bulma was still a little pissed that she hadn't been there to see the last bolt go into place. The suite also contained two vanity tables for the women to use and a large bathroom with a tub large enough for at minimum two people to use at the same time.
There was a set of rooms for Gohan, with a personal outside entry way so he could come and go as he pleased since he was practically grown. His rooms included a study where he could do his homework or help the younger kids with theirs and a guest room for when Videl stayed over for the night. None of the parents really thought she was using it, but Vegeta mentioned off-hand that Saiya-jin tended to pick their perfect matches early in life and was convinced that Videl would be around for a very long time to come.
Trunks and Goten each had their own fairly-large bedroom, but within the first forty-eight hours in the house they'd moved the beds and dressers into one of the rooms and shifted all their toys and non-bedroom furniture into the other to make a shared bedroom and a large playroom instead. No one was too surprised, and Chichi's only concern was that the bookshelves were too heavy for the boys to have attempted moving on their own.
All of their friends, basically their extended family, came to visit them for a housewarming party the first weekend in the new house. Not one person was surprised that the Son and Briefs families had successfully blended into a single entity, nor did anyone have a bad thing to say regarding the fact that all four adults were sleeping together.
All in all, life was good.
Until the next invasion attempt, but that's a story for another day.