After events of Undertale.... You came back to Snowdin, or to be specific Snow Forest and see sentry station it was empty... As you walk around, feeling somewhat sad and nostalgic... As you notice a Sans as he turns around to look at you, his expression was somewhat sad or just nostalgic or just bittersweet, his grin wasn't as wide as before as he pulls out a hotdog and ketchup bottle on other hand as he says this

Sans: hey kid, do you wanna weiner in your mouth?

However, you feel bad about him in like caring about him as you without hesitation agreed as he tossed you a hotdog with ketchup on it as you eat hotdog... His grin widens a bit from seeing you eating hotdog... Despite everything, it's still you, same as always...