Alphys returned home from a quick shopping trip, a few bags in her hands. Nothing important, just some more ramen and these really cute swirly straws she found in the clearance aisle. She got a bag of spicy beef jerky for Undyne to try, if she wanted.
Alphys left the bags in the kitchen, looking around. Undyne must be in their room, since she wasn't out here watching human wrestling- her new favorite thing. She picked up the beef jerky to show to Undyne and walked to their room.
"Undyne, I'm home. I got this thing called bee-"
But before Alphys could finish, she was cut off by her own shock.
Undyne was sitting on their bed, cross-legged, with several papers scattered around her. Not just any papers, but 'special' ones. Alphys recognized them instantly. The only time she used frilly pink paper was when she was writing fanfiction (or, often, 'friendfiction'). And the papers scattered around Undyne were all frilly and pink. Even within Alphys moment of scared shock, she knew that those had to be the fanfiction she had written of her and Undyne being together, before they actually were together. Cheesy, romantic things. Dates at the dumpster, Undyne leaning down to kiss her, Undyne protecting her and lifting her and swinging her around happily.
Horrible, horrible stuff like that.
"U-U-U-Und-Undyne.." Alphys spattered, dropping the bag of beef jerky, her entire body scrunching up in fear and embarrassment, "I-I-I can ex-explain!"
"What is this stuff?" Undyne asked, her voice and face showing no emotions to help Alphys figure out how she was feeling.
"W-Well th-that's, uh…. Umm….." Alphys led off slowly, sweating wildly.
"You never told me you had an alternate world hoppy machiney!" Undyne suddenly shouted, a smile growing on her face, pointing to all the papers.
"Wait… What?" Alphys whispered, hardly audible. It felt as if a physical blanket of confusion was falling on her. First off, that's fanfiction, not records of an alternate world. Second, there is no such thing as an 'alternate world hoppy machiney'. Third, and most importantly: What?!
"Yeah! All this stuff you wrote! It's from all those different worlds you went to in your machine, right? Like that one you showed me in that one anime with the time-traveling alien thing, remember? So all this stuff happened in the other worlds?" Undyne explained rapidly, flipping through the papers.
Suddenly, Alphys understood.
Undyne didn't realize those were just manifestations of Alphys love, but rather they were records and reports from Alphys visits to alternate time lines or something.
And she wasn't freaking out in anger, which was a pretty important part, too.
"Oh, uh… S-Sure?" Alphys replied, not really knowing what to say. It's not like most other situations, where truth was vital. This was an… 'Exception'.
"How come in all those other worlds, we got together way earlier?" Undyne asked innocently, skimming through the papers and handing them to Alphys, as if she hadn't seen them before.
"Who knows…" Alphys gulped, trying to find an excuse to burn these papers immediately.
"So where's this super cool machine? I wanna go to the other world and fight me!" Undyne shouted, patting her muscles in pride.
"It, uh, broke… Back underground… Sorry," Alphys shrugged, as if it was saddening to her to remember that the machine broke.
"Aw, sorry, Alphys," Undyne pouted, "But one day, maybe you'll make another, and I'll fight the other version of myself!"
Alphys smiled weakly in agreement to Undyne, who was grinning while imaginging the amazing fight against herself.
Alphys stepped out of the room for one moment, and was finally able to let out the pained, exasperated breath she had been holding.
"I will never write fanfiction again for as long as I live…" She promised herself, tearing the papers into little shreds. Why she even kept them in the first place was beyond her.
Suddenly, she heard a scream from their room, and she dropped the shreds and rushed back in. Undyne was jumping up and down on the bed, fanning her mouth.
"Hot, hot, hot!" She bellowed loudly, stomping her feet on the bed.
Alphys glanced down and noticed a half-empty bag of spicy beef jerky. Well, at least she tried them.