Let the Embarrassment Begin....

So it has come to the time in this journey where my son can embarrass me. My sweet little boy has somewhere (truly, I don't know where) picked up the "s" word. He alerted me to this by saying "Ah, s****" in a department store one day. Repeatedly. I over-reacted a bit and made it even more enticing for him to say it. So over the past couple weeks, if he says it, I calmly say "Ryan, we don't say that word." He seemed to get it. Great! Problem nipped in the bud. So we were at Ryan's dentist today and he was laying on the chair (which, by the way, he freaked out on when they tried to lay him down and kept saying "Mama, don't let me fall." I know they were thinking I've dropped the child and probably more than once by his reaction. WHICH I HAVEN'T). Anyhoo, he was laying on the chair and the dental assistant was telling me "I really want you to focus on blah blah blah...(I was already obviously focusing on ummm, what was it she was saying again?) and Ryan said "focus!" And she said, "yeah, that's a new word, huh?" To which Ryan promptly replied, "yeah and we don't say sh**!" True story. Honestly, I thought it was funnier than I was embarrassed. Does that make me a bad Mom? Or did I pass bad when my son started using the word at 2 and 1/2?