The next day...
Lincoln walked out of his room... And the first person he found was Lisa, who was about to get ready to go into the vents. "Lisa," the boy stated, causing the little genius to lose her balance and hit the ground. "We have to talk."
"What would you like to talk about, my dear brother?" the scientist inquired, trying to not act suspiciously.
"I want to know exactly what you did in the bathroom that forced me and Lori to share a bath together," the boy asked. "Having you come out of there with the suggestion just as we were wondering who should go first, just seems a bit too suspicious in my eyes."
The scientist looked away, then slowly started to walk away. "Lisa, don't try to get away!" Lincoln growled. "Tell me what's your deal!"
"...Lincoln, can I trust you?" Lisa asked.
"I'm your brother, Lisa. If you can't trust me, who can you trust?"
"Fair enough," the smart brunete took a deep breath and explained herself. "Listen, a couple days ago, our sisters started to tease me over the fact that I needed some company in order to use the bathroom to reach the sink, brush my teeth, stuff like that. So, I figured that the only way to stop their teasing, was to have them suffer the same awkwardness I felt when I shared the bathroom!"
"And what about the whole thing with Lola and Lana?!" Lincoln blurted. "Oh wait, you probably don't know about that-"
"Actually, I do know about it. How, that's not important, but it's probably just some sort of ghost story Luna came up with to scare you, and I definitely didn't believe that story was true at all," the scientist replied, looking to her left and right before adding, "She's not particularly nice, and she can be quite malicious and sadistic, so the farther away you are from her, the better."
"Okay, with that established, what do I have to do in order to convince you to stop this nonsense?" Lincoln asked. "Because getting revenge on our sisters is one thing, but including me into the mess when I didn't even know about the teasing is another thing altogether!"
"Listen, the experiment is close to ending, you just need to share some awkward time with Luan and Lynn and boom, experiment's over!" the scientist got on her knees and clasped her hands. "But please, don't tell them anything about this! If there's anybody that knows how horrible it is to be denied of the satisfaction of getting revenge on your tormentors, its you! And maybe anybody who's dealt with Lola."
Then, after thinking about it, the brunette corrected herself. "Actually, definitely anybody who's ever dealt with Lola."
"Alright, I won't tell them anything," the boy answered, rolling his eyes in exasperation. "But I want YOU to stop this nonsense right now!"
"W-What?! Lincoln, didn't you hear me just a moment ago?! I'm this close to finally getting some payback for all the teasing!" Lisa pleaded.
"You didn't let me finish." Lincoln added. "I have an idea as to how we can make this a win-win situation for both of us."
A Little While Later...
Lincoln, alongside his sisters and parents, were bathing together in the bathtub, and needless to say, it was a bit cramped. "So this is what everybody's been teasing Lisa about?" Leni inquired, raising an eyebrow.
"Yes," the scientist stated.
"Dang, do you have to deal with this daily?" Luna asked, taking a look around.
"No, Lincoln just thought this was necessary to show everybody what you were teasing me about," Lisa added. "Anyway, did it work? Will you continue teasing me about it?"
"Will we continue teasing you? Yes. Will we continue teasing you about sharing the bathroom with people? No." Lori answered. "I mean, Leni, Luna and I had an literally awkward experience with Lincoln-"
"Well, Lori and Leni did," Luna corrected.
"And, well, since the teasing made this happen," Leni added, wincing at the thought. "I think, like, it would be better if we stopped teasing you, right?"
Everybody nodded in agreement. "And there you have it, folks," Lincoln told to the readers. "Sharing the bathroom with people may be considered odd, but in truth, it's nothing out of the ordinary. And if people do tease you about it, there are several ways you can deal with it."
And then he turned stern. "That doesn't include some stupid, awkward experiment.
"Lincoln, is that your crotch finger touching my butt?" Luan inquired.
The boy flinched as the prankster laughed. "I'm just joking!" she said.
The rest of the family laughed, at least up until the bathtub broke through the ground and plummeted to the ground.