Sassy Baby

My almost-11-month-old son has started sassing me. It's not just my imagination, like I thought the first couple of times. I see him doing something he's not supposed to and say "No." He knows "no"; it means "stop what you're doing briefly, look at mom and go back to what you were doing". Now, however, when I say "no", he pauses what he's doing, looks me in the eye and says "Da!" before going back to what he was doing! If I say no again, he says da again, with the same amount of force I say no. "Da" is a word he uses to mean "dog", "Dad" and, when pointing "that" or "there". I'm not sure if it also means "yes" or if he's telling me that the dog or Chas would let him. The reason for this was right beneath my nose - Sassy brand toys. I registered for these toys and even bought him a couple, but they must have subliminal messages telling children to disrespect their parents. That's why they chose Sassy as a brand name. I can't imagine there's any other reason.