Apparently not an actual word, funly is used to describe someone who does something in a fun way.
She teaches funly.
Having qualities traditionally ascribed to fun, such as excitement or laughing.
Archaic: in a funly manner.
Tim: What about the funliness factor?
Theodore: The level of funliness will be matched only by the level of manliness at the party, so grab your steel mits and whiskey.