Y’know those dreams about one’s crush liking them back? And then the feeling they get when they wake up and realize it was all just a dream? How would the skeletons react when experiencing this?
UT!Sans: It's a bittersweet conundrum for him. On the one hand, he's so disappointed that it was all just a dream. But on the other, it wasn't a nightmare. Frisk is such a sweet and powerful presence in his life that his nightmares have turned to cute, innocent fantasies of the two of them together.
UT!Papyrus: Papyrus canonically doesn't sleep that much, so this dream is a rare occurrence, perhaps a nocturnal message from fate. Like his brother, he wakes up just a little grumpy that it wasn't real. In fact, this makes him not want to sleep anymore because he doesn't want that wild imagination in his skull to have an opportunity to jape him so cruelly again.
UF!Sans: He cries when he realizes it was all just a dream. He grabs his pillow that he'd been cuddling and kissing in his sleep and throws it to the floor. "like she'd ever...!" He hisses, but then he retrieves it a few minutes later and curls back up under the blankets. 'at least i can kiss 'er in my dreams...' he thinks, before drifting off once more.
UF!Papyrus: As with his Undertale counterpart, he sees the dream as a cruel trick that his mind has played on him, a wondrous, too-good-to-be-true vision to punish him for not staying wide-socketed and alert. Oh sure, if Sans or Undyne somehow ever hear about the dream, he'll scoff and say that he can create a reality with Chara so beauteous that the sugary sweet dream would seem like a mediocre nightmare... but that's really him talking himself up, as usual. He ponders alone why she can't love him like in his fantasy.
US!Sans: He awakes with his boney lips pressed softly against his pillow, his arms trapping it in an embrace against his chest. He too awakes feeling just a little down that none of what he saw was true, that amazing, stunning, nearly blinding smile from his beloved sunshine merely a hope inside a dream... But then he remembers that he can make that happen in reality! He rushes right out of bed, then he's on his way to visit Frisk, to try and see that beautiful, genuine smile brought by him and him alone.
US!Papyrus: I mentioned in a past post or two that, though he isn't completely aware of it, sometimes Papyrus has visions of the future and alternate timelines. Well, by this point he's wondering if he has some form of foresight, and he wants to hold onto the hope that what he saw was something that's actually attainable. That it wasn't just a silly fantasy, or a reality exclusive to one of his other selves.
SF!Sans: "TCH. WHAT FRIVOLOUS NONSENSE..." He mutters when he opens his sockets and comes to his senses. In truth, he was far more touched by the dream than he would ever be willing to admit. Sans doesn't sleep that much since he's so busy, and his body can store enough energy that he won't have to again for a while - but he finds his mind wandering back to the scenes in his dream more than once. It's even a little difficult for him to look Frisk in the face the next few times they meet, something that throws her completely off.
SF!Papyrus: He wonders at first if it was inappropriate for his mind to dream such things, even though what he witnessed was entirely innocent. There's a sense of shame that follows him, since he's not used to experiencing such things - being selfish and having her love all for himself, even if only for that fantastical moment. Unlike many of the other skeletons, once he stops beating himself up over having it in the first place, Papyrus can only feel happiness when he thinks about the love he and his human shared, though it wasn't real.
G!Sans: G wakes up with a dumb grin on his face. He turns over and just laughs and laughs into his pillow until his ribs start to hurt. Sure it was a nice dream and it sucked that it wasn't real, especially since he's hinted around and flirted with Frisk for what's felt like ages. But he decides that he's gonna use this dream to his advantage. The mad lad actually tells Frisk all about it, and he's gonna gauge her reaction. If she isn't weirded out by it or doesn't brush off what he says as a joke, then this could lead to an actual confession, he thinks!
G!Papyrus: Green is so flustered. The blush on his cheekbones present when he wakes follows him throughout the day. He can't look at Chara in the eyes for a long time afterward, and it annoys her greatly. It also annoys Undyne, so she grabs him (much to Alphys's dismay) and demands to know what's going on. He barely gets it out that he had a dream about Chara; Undyne's shocked beyond words he'd think of something so scandalous, unconsciously or not... but she quickly regains her wits when she finds out that the two were just holding hands in his little nighttime fantasy - there wasn't even any smooching.
W.D. Gaster: He takes the dream as a sign that the moment he's been waiting for has finally come. Gaster's been trying to woo the lovely Frisk for a while now, taking his time with courting her. But even though he's a man of science (and magic), he's also a firm believer of messages from the beyond. He gets ready for the day and begins to plan his proposal; that he and Frisk should, how the humans say, go steady.
