"Phew, it reeks in here...", you hear her mumble, "...of what, actually? Disgusting smell." Then she notices the cum spots on the floor, and your freshly dripping penis. Her face quickly turns to anger, and secretly you feel sad for making your mistress angry. "That was the last time", she says, "we can't keep telling you, you're not a pup anymore. We're gonna get you fixed, and we're gonna do it today." She grabs you by your collar, but you whimper and struggle as you can tell where you're going. This seems to annoy her even more. "I suggest you'd cooperate. You have a choice between just being sterilised or becoming female. I don't think you'll enjoy the latter." Upon hearing this, you stop resisting and walk after her. Not only because you might be turned female - hell, you might even enjoy it - but a part of your mind commands you to be loyal to your mistress. She now turns around, thinks for a moment and then says:"Actually, there's another option. We also have regression magic at our disposal, so if you're so desperate to masturbate on our carpet all the time, you might as well have the age for it. Gives us another chance to properly raise you, as well. So what'll it be? Just bark once for sterilization, twice for feminization or thrice for regression."