"I was thinking it would be fun for you; it sounds like you would not have previous experience with being - able to be naughty, in that particular way, of taunting danger and seeing it unable to punish you. Are you currently being punished, just to check?"
Albe is guiding Merrin's foot through the lava, first rapidly and shallowly, then more slowly and deeply, her hand very firmly in control of Merrin's foot at all times.
(It feels increasingly hot, not quite painful yet.)