Hmm... [Ivan hums thoughtfully and proceeds to prod the snake again. Deciding it was done, he picks it up and blows on it fruitlessly before taking a bite.]

Ow--! [Hot! Who would have thunk it?! Ivan still takes a few more bites despite the heat. After he's eaten a good chunk of the snake it's only then that he decides to answer Roy.]

Are there limitations on this favour?