You had acted quickly with the experimental antidote and it gave you your human mind -- it was time to take action again to preserve it.
With your superior lizardman strength you managed to push Andrea's heaving breasts away from your mouth, though a little bit managed to slip past your maw. You couldn't help but notice how..."sweet", for lack of a better term, it was, which seemed to excite your lizardman body as you let out a lustful growl despite yourself. Even as you managed to keep her breasts away from your maw you could feel it travel inside you, your lizardman body seemingly reacting to it by your heartbeat getting stronger, your lizard blood coursing through faster. You could see your right arm, currently holding Andrea back, get visibly thicker and stronger and made its job of holding Andrea that much easier to do as the milk-laced blood reached that part of your body. You couldn't see it, but you could feel it also reach the rest of your body...
...including your twin reptilian dicks, which grew larger and stiffer. Andrea let out another lustful growl, driven by her lizardwoman instinct to finish your conversion and the feeling of your member growing inside her. Unable to get you to drink any more of her milk, she pushes her cloaca farther up your rod while also grabbing your free one, teasing it to drive you up the wall further. Your human mind is under assault from all these sensations and feelings, making it harder and harder to hold back until you couldn't any more, reaching a climax and letting loose a reptilian roar as you shot a load of spunk out your two dicks. Andrea lets out one of her own as she feels your results both outside and inside her, her breasts squirting out milk in response all over your muscled-up lizardman body.