Soon the Marys could feel a familiar sensation occurring at the base of their udder. They looked down and sure enough four large teats were sprouting from the bottom of their udder! One Mary began to massage the udder causing those familiar pleasurable sensations up each of them.
"Mmmmmm... do that again..." the other Mary moaned.
The udder sag as it filled with milk while both Marys began to massage the udder.
"This feels soooo good..." one Mary moaned.
"I had nearly forgotten how good this felt..." whispered the other.
But as they became lost in their conjoined pleasure they didn't notice another change happening to their bodies. They could feel their chests growing heavier but paid them no mind as they closed their eyes and felt the warm milk filling their udder. They massaging became slower as well but not because they were growing tired, but simply because it became much more difficult to even move their hands. Soon the massaging ceased all together.
"Why'ed we stop?"
"I dunno? I was trying to... AHHHHH!!!"
The Marys looked down to see that their hand were no longer existent. From the wrist down their hands had been swallowed by their large udder. Their arm were now connected to their udder! As they attempted to pull them out nothing happened except pulling painfully on their udders.
"Why the heck is this happening?" yelled one Mary as she watched the flesh from their lower arms sink into their sides and udder.
Soon their arms disappeared all together into their torsos leaving both Marys armless.
Only then did one of them spot their other new change.
"AHHH Mary! Look at your breasts... look at my breasts! They're UDDERS!!!" she yelled as she tried to point only managing to twist her torso jiggling her new udders. Sure enough each of their breasts had swelled to the size of small udders and had grown four erect teats dripping with milk at the end of each.
"Uhhhh... Mary?" one began to say, "My breasts feel heavy... I think we need to be milked!"