Both?

A growl passes your lips as your competing halves come to an accord, though your former reason probably didn't mean it like this. There was something very wrong here. She was NOT to give you orders, even if they were ones you liked.

You roll her onto her back again, her gigantic belly sloshing audibly through her surprise. You roughly pin her body to the bed, staring her in the eyes until she looks away in submission. "I...I'm sorry, Master. I forgot my place. Please forgive me..." She can't look at you as she says it, her gaze not even wandering towards yours.

"I think you need something a bit more to make sure it's not forgotten again" you say, grinning lustfully. As you grab your cock, she tenses in real fear, afraid you'll try to impregnate her again. Knowing that could really kill her this time, you know better and pick a different hole. As far as you knew, she had been an anal virgin until you thrust in, though you wonder if your size would have brought her to tears regardless. Your pre-cum lubricates the entrance quickly, and you thrust hard several times in order to get your cock all the way in.

Amy seems at a loss for words, not wanting to anger you further with pleas to stop even through the pain. Her bowels seem to adjust to fit you, rather than the other way around, and you cram the last inch into her after five minutes of pounding. You roughly fondle her enlarged tits, pinching the nipples before leaning over to suckle. As you do, you are greeted by a flow of rich milk, drawing a moan from Amy in spite of herself.

"So my little fuck toy is lactating, hmm? You like getting milked, huh? Milked while getting your ass fucked." She says nothing to you, only turning red in response. A quick jab with your cock gets a yelp. "I asked you a question." She slowly nodded her head, still not looking at you. A second jab and a growl precedes your command. "Look at me and say it so that the world can hear you!"

Sobbing, she submits, the remaining dominant streak hiding beneath her submissive demeanor breaking as she does so. "Yes, Master, I do! I love it when you fuck my ass with your huge cock and milk my titties! I'm so sorry for trying to usurp you, Master! I beg you to forgive me!" A lick along her neck and onto her face gets her attention as your anger subsides a little. "Much better. Now tell me, ****; do you want me to fuck your ass till I cum in you? Should I drink all of your milk?"

"M-Master, I exist only for you. Telling you what I want would be presumptuous." You lap at her nipples, sending shivers down her spine. "Close, my dear. Saying what you want and telling me to do what you want are two very different things. You may ask me for favors, but never command them." As you resume suckling, she squeaks again, a few more fucks into her ass driving her wild. "Do you understand?" "I do, Master. Please fuck my little ass and cum inside me whenever you wish. Having you drink my milk honors me, so, please, I am here when you command it!"

With that, you let up. Her face goes from lust to confusion, then to anguish as you pull your cock from her ass. You are surprised to find it is completely clean, the result of, perhaps, the transformation having some other unseen side effects. She wiggles her butt at the vacancy, clearly wanting you to continue. "Oh, Master, why?"

You get up and grab the remains of her clothes, tearing strips from them and tying her arms to the bedposts. Not too tight, but enough where she can't get free. "Your punishment, of course." You chuckle, knowing how maddeningly close to orgasm she is. "I do believe I'll find myself more mates now. By the time I return, I expect you'll have learned your lesson rather well."

Her sobbing plea for you to come back and fuck her only serves to increase your arousal. You have a pretty good guess as to what caused her to change too, but that would be an experiment to run with the next female that caught your attention. Several trails are already clear to you as you step out into your back yard. It's only a matter of which one to follow into the night.