1. An incredibly annoying way of stating that you just don't want to tell them something; might be for personal reasons. (Knowing that you cannot get younger; it therefore means one will never tell them what you are referring to.)
Caitlynn: Why won't you look at my face when we make love!?
Me: *turns away and thinks to self "ah crap, here we go again... c'mon, think of something!* ...I'll tell you when you're younger...
Me: *turns away and thinks to self "ah crap, here we go again... c'mon, think of something!* ...I'll tell you when you're younger...
by The OPB: Original Purple Belt October 11, 2010