azany-ut:

Bonus for THIS ARTWORK

The same evening. One can’t say that the decision to be cruel to Sans was easy for Papyrus. Anyway, there are only first attempts of Papyrus to position himself like “Boss”. The time will pass, the self-deceptiveness and constantly rising EXP will have effect, so Papyrus will really hate Sans and think that he is pathetic nobody.
And Sans… Sans is just broken, poor fellah. He even doesn’t have places to go – cause only with his Boss he can be kind of safe.