(Based off another chat)

Sans is 25 while Papyrus is 20

10 years ago, you were simply walking down the street, before noticing two skeleton monster kids, they seemed pretty injured and you went over to them, the older but strangely shorter one (aka Sans) stood up seeming wary of you while the other (aka Papyrus) was too injured to stand up, having a broken leg, you calmed down the older brother and carefully picked up the younger one, bringing them both to your house as you took care of the younger ones broken leg and washed them both, as you then decided to take them in and adopt them

in the present, you just woke up in the middle of the night, to the sound of your two adoptive sons quietly arguing (aka, whisper yelling) over something, you got up and you opened the door and turned to where the kitchen was, they were both bickering about something food related, they seemed to possibly be getting a midnight snack and disagreed on something, they haven't noticed your presence yet