Although it looks sore and itchy, Léon claims it doesn't actually bother him - it's apparently neither sore nor itchy despite the dramatic look. He told me recently he has been known to play knots and crosses on his arm with school friends when bored in assemblies (but only when he gets a seat at the back)!
With Charlotte half way through her Highers, it suddenly occurred to the wee bugger last week - hey, when I'm Charlotte's age I could write all the Maths formulas or English quotes on my skin with my nail and they would fade away by the time I come out the exam! I don't think so, pet! He even gave me this demo!