My 10 week old Jax loves play time with me,whether it's making him chase the end of a stick,contact play or tug of war.He loves it all. There has been a couple times where we are playing and he almost lays down,similar to a sprawl and he will growl and bark a bit. He doesn't seem aggressive while doing so his tail still wags and I just tell him "no sir" in a firm voice and he will stop. I just don't know if he's just playing or trying to test me or what? Is it acceptable for him to do so or is it not to be tolerated? Any input would be appreciated,thanks!