You were Kris, the creepy human kid next door. The little puny creature that your adopted parents took pity on. Hah! Asgore and Toriel even felt the need to stay together so they could take care of you, that just made you feel even more pathetic.
It was very hard being the only human in a town full of monsters. They never under your instincts or culture...At least Asgore, Toriel, and your adoptive brother Asriel tried to understand- and ever since you got close with Susie she did too! Noelle and her family always treated you kindly, sometimes she could be skittish of you but that was probably bc she was scared of "the humans under her bed".
And then you also got in trouble for biting someone once, but they should really learn that's how humans react when threatened. Still, not everyone in town was so nice to you.
Oh...and you might've just bitten someone in front of you- hey! it wasn't your fault! They were the ones trying to pick you up all out of nowhere...hopefully Toriel and Asgore would understand.
Speaking of them...
"Kris? Where are you?" Came the soothing sound of your mother's worried voice
"You really shouldn't be going out alone by yourself" Came the booming gruff voice of your dad