Where I give my opinions of Undertale ship. Feel free to share your own!
I think that is good they both like puns and all and silly things too.
Ewww... I hate ship... Toriel is waaaaaaayyyyy too old for Sans... They are about 20 years apart!
My only reason for not shipping it is because she's such a motherly figure. I could see them being great friends, and Toriel being her normal, motherly self to him, but nothing more.
.. Soriel shippers pretty much say: 'If you love puns your shipped with Sans/Toriel'
Also, I see Toriel as a motherly figure and she WAS married, so she can be older than Sans or way much older. She even had a child to start off with!
This is my NOTP, and I have reasons for it.
I'm too lazy to post them though.
I don't ship it but I respect it. Besides it's not like I'm a Frans Fangirl who would rage at you for shipping something else.