Facesitting is a great way for a mature lady to put a young disobeying slave back in line. Most young guys are scared by the experience of a mature mistress - but a mature mistress might probably know the limits of a less experienced slave and can take him near-by but not over the limit based on her experience.
Whether it's your teacher from old school times or the sexy mother of your best friend - you surely imagined being punished by an older lady at least once? Why not try it?