The bottom image (pun intended) I resimulated the jiggle to be less firm and slightly slower, to make it flow better in the edit.

The bottom image (pun again intended) is the one you'll find in the edit, but on their own, which one do you prefer? Let me know in the replies!

"You are never visiting my lab ever again."

She gasped. Jenny felt like she had just had 100 orgasms in a row. She opened her eyes to see the whole room covered in milk. Her milk. She was shocked at how much there was and how far it had gone.

Her eyes swiveled to Sally, who was sitting in-front of her, arms crossed.

She was almost shocked at how incredible it felt as the milk gushed from her breasts, each spray sending electricity all over her body, causing her to moan uncontrollably.

Eventually the milk started to slow down. She pushed her knees together, trying to squeeze that last little bit of electricity.

Jenny's nipples exploded with milk. She cried out as a shower of white liquid sprayed from her nipples, coating the lab, the equipment and Sally with a sweet-smelling, warm liquid.

Jenny was dripping, and not only from her boobs.

"I... uh..." Jenny couldn't reply. All the sensations were becoming too much for her.

"Oh damn, are you getting bigger again?" Sally had concern on her face now.

"I think... I think something's coming!" Jenny managed to get out.

"Oh shit, it's the milk! We need to get you to the bathroom before-"

In fact she could feel the remains of her tank top stretching again as the material became taut across her chest. Her nipples were already fully hard, but she could feel them getting bigger now as well.

"Hello, are you listening?!" Sally interjected.

Each slight breath of air across her boobs felt like someone brushing a feather across them and her nipples were getting hard.

Something else stirred deep within her though. Sally's voice no longer registering, Jenny felt something from within her boobs. Like they were filling with something.

"The issue is that it's way too effective. I can't figure out a way to program in the size or the amount of milk." Sally explained.

Jenny was only half listening. Her mind was distracted not only by the weight of her new chest, but also how sensitive they were.

"And they're going to-"

"Yup."

"Okay so how long does it-" Jenny was cut off as her chest tightened and swelled, ripping open her tank top and leaving her with a set of massive mammaries.

"Oh no, is this another muscle machine? I just got back to my normal size after I messed with your last one."

"No, this is something different. It's designed for mothers who are having trouble making and expressing milk."

"Oh... right. Does that mean-"

"Yup."

"So my-"

"Yup."

"Looks like you'll need a few sizes up. I think Jimmy could lend you a pair?"

Suddenly Rina's leggings swelled as her ass blew up right before their eyes. They stretched dangerously tight before ripping open, causing her to stumble forwards and her now voluminous ass to jiggle and ripple.

"What the fuck?! I just fit into these leggings!" Rina yelled.

"I think a tablespoon per bottle is enough for a pre-workout. Should last you a couple months."

Rina set down her now empty bottle.

"Ummm, what was that?"

A rumbling suddenly came from her stomach.

"Ohhhh, yeah this happened to Jimmy, just before-"

"Just don't take too much at once or it all goes to your ass. Jimmy found that out the hard way and now he gets hit on at the gym. By like, everyone." he said, as Rina scooped 3 heaping cups into her bottle and filled it with water.