I'm too lazy to answer why I ship this everytime, so instead I'm just gonna make this and everytime someone asks me I'm gonna send them a link to this place... so, if you are here for that reason, let's just start with why I don't ship other things like Soriel and instead I ship this:
Sans and Toriel have one thing in common, they like bad puns, and that's it, but now try to imagine Sans as a dad, let's start saying that he is lazy, too lazy, look at his house, full of socks everywere, his bedroom is even worse, and I don't think Toriel would like that.
Also, not only he likes bad puns, but also he likes to make fun of people to make them