She goes back to her dorm room

Gwen looked at the watch-like device. She pressed the same button that pushed the big cylinder upward. That brought it downwards and turned it back "off" she supposed as the diamond became an hourglass again.

She looked down at herself. A few minutes ago her breasts were a small average B cup. Now they were huge double Ds. "No way, my breasts are huge" she said cupping her giant milkers. They felt soft and squishy and looked huge and round with cleavage sticking out above her hoodie and shirt collar. They were also much more sensitive as she poked one and it felt like lightning went down her body.

"Oooh" she said blushing. They were soft, made her feel good and were truly a part of her. She jiggled them some more and watched as they bounced up and down quite a lot letting them go before they settled back into place.

Putting her huge new jugs aside she had to figure out how she got them and what this watch was. She looked at it studying it. It changed its appearance drastically. Now it looked more like a thin regular watch and blue. She observed the tubes and saw energy going through them. At the same time she felt a tingle on the wrist the watch was attached to.

"I gotta tell Valerie about this" Gwen said. Realizing that the crash would attract attention as smoke was still rising from the crater the pod carrying the watch was in, she ran back to her dorm, her breasts jiggling up and down as she ran.

The door opened and Valerie saw Gwen come in.

"Gwen! There was a crash and you weren't here i was worried about you-" Valerie said being taken off guard by Gwen's new assets.

"Oh my God Gwen what happened?? Your tits are huge" Valerie said happily and curiously. She jumped over to the redhead girl and began fondling her new mammeries, squishing and kneading them like dough.

"Uuoooh Valerie...cut it oouut" Gwen said.

"Wow, these really *are* real, and sensitive" she responded. "I may have to...take them in a little more~" Valerie said wiggling her fingers mischievously.

"Not now Val. Look, the reason i have these....boobs is because of this thing that attached to my wrist" Gwen said pointing to the watch that came from space.

"Oooh fancy watch. Where'd you find it" Valerie said.

"At the crash site" Gwen said. "There *was* a crash and this watch was in the thing that crashed down" she explained. "It made me grow these boobs" she said.

"We-heh-heel what are you complaining about? Keep it. If it gave you them bazongas and you feel fine no big thing right"? Valerie said.

"Uh, yes big thing! It doesn't come off" she said trying to pull it but it was as if it was glued to her.

"Plus, it has this weird dial thing that pops up when i press this button" she said. She pressed the button she pressed outside. The faceplate popped up revealing the cylinder with circuit lines from before. The hourglass turned into a diamond and a silhouette of some stranger shaped figure was seen.

"Oooh real nice. Wonder what happens if you push it back down" Valerie said. Following up on that curious statement she pressed down the button herself.

At that instant Gwen felt something she never felt before. Strong energy was being injected into her body. She felt it bend and stretch, but she didnt feel that much pain. The light died down and she was...

(Following chapters for which alien Gwen becomes must be listed by their species name which you can find on the ben 10 wiki.)