Much like his two older sisters, Luke Dunphy marches to the beat of his own drum. It's an offbeat beat to say the least. Sometimes Luke gets his head stuck in the banister, other times he jumps around on the trampoline while in his underwear with a box on his head. Told ya he was offbeat.
But Luke is epitomizes the innocence of youth. He didn't think it was a big deal to mention that his mom thought her dad's new wife was a "coal digger." Of course, Luke got the phrase wrong. What he meant was that Claire thought Gloria was a "gold digger." Ahhh. Careful what you say around this guy.