Your son's scarf is completely awesome - and I think its awesome that an 18 yr old guy will learn to knit. My brother is 17 - he learned to sew when he was 3 (my mom taught us both), but now refuses any association with thread or yarn. None of the other guys I know would ever admit to knowing how to knit, whether they know or not.
I'm curious about these scarves knit 3 on 1. Is it the same basic technique as for knitting two layers? anyways, all of your stuff is gorgeous, good job!