Gaster is a busy skeleton man, most of the time he spends working on his experiments for the kingdom, in a small workshop inside his house, but it's not easy with two adorable skeleton kids running around.

you saw Gaster carrying Papyrus while with one of his extra hands he was holding a sleeping Sans

"Are you the babysitter?....wait...a human? uhg...never mind, I'll hire you, I'm desperate"