You enlarge her boobs a second time. Sorry.

You do your best to concentrate on making Brittany's boobs smaller again, but the insane clopping of her gigantic breasts fills your head with a single though: "Holy shit look at those fat titties and they're giving me a titty fuck..." Cum starts pumping out from the massive cleavage where your cock has disappeared completely. Brittany notices this and slows down her movements into slow, milking motions. You cock continues twitching and pumping out one huge spurt of cum after another. It's almost as if your cock has decided to keep cumming until whatever it current target is has been fully covered in spunk. Eventually Brittany stops her milking motions and concentrates on dodging cum from hitting her face or arms. She just stares at the never-ending money shot with her mouth hanging open. Finally, after what feels like a minute, your cock stops pumping out cum. You look at the glistening mess that truly covers every square inch of Brittany's enormous breasts.

You back away from Brittany as her breasts flesh starts to pulsate again. To your horror, you notices them gaining fat with every pulse. Large ripples travel through her boob flesh. "No way, what the hell", Brittany yells in panic. The growth doesn't stop until the extend past her knees. The enormous weight of the boobs seems to pin her in place.