Board Thread:General Discussion/@comment-26826023-20160201071856/@comment-27620479-20160405062807

No, that definitely isn't.

Sans actively tries to befriend, warn, and satisfy the protagonist (presumably to the best of his abilities). He also has Papyrus on his side, and the promise he made to Toriel to prevent any hostile interaction.

The interesting part comes after that, and is up to personal interpretation.