You have been Sans's roommate for a while now, about two years, in fact. He was acting like his normal lazy self while sleeping on the couch, but you see what it looks like to be a vine growing on his arms.

You become suspicious and roll his sleeve up only to see more vines. You opened his jacket at the most horrifying yet beautiful sight, which meets your eyes... flowers and vines all over his ribs.

Sans woke up from you opening his jacket, a look of fear on his face. I-I can explain!