He tells her (mostly)

Karma was his best friend, he couldn't lie to her. Plus it would be quite to hide his changes to her, being in the same room hours a day.

"I, got this marker, and when you write something on someone's body. It changes accordingly." He finally said.

Karma looked at him with a suspicious look.

"Riiight..."

"What ? You have a better explanation for me gaining 50 pounds of muscles ?"

Karma frowned, looking down for a moment. Then looked back at Finn

"Good point. But it's still... stupid. I guess you can prove what you say, no ?"

"Well, sure, but let me take a shower first, it goes away with soap... I hope..."

Finn rushed then to the showers of that floor to wash his arm. As he was rubbing the text off, which was harder than expected, his muscles started to fade into his old shape. He was thinking about brushing off the high stamina, when he suddenly heard something being teared and a "Holly Shit ! Shit ! Shit ! Fuck !"

It was Karma's voice. What the heck was she doing in the guy's showers ? That's when the marker came in mind.

A little bit in panic, he opened just enough of the curtain to take a look. Karma was there, her top had a long tear due to now having such a huge rack it was probably twice the size of her head. She was trying to keep her massive breasts to come out when she saw him.

"Don't-Don't look !!" She yelled while turning her back to him, red faced.

Finn closed the curtain and cut the shower.

"For fuck sake, you could have waited !" He grumbled.

"Sorry, I just wanted to see by myself..." She told him.

Dried, the high stamina marking still on his body, Finn put his towel around his waist and went out of the stall. Karma had her back turned to him, but she had teared the last part of her top and was trying to do something that made her boobs go right and left.

"What are you doing again ?" Finn asked, exasperated.

"I'm trying to clean it off, but with theses fat bags, I can't do it properly..." She raged.

After a moment, she turned to Finn, her hands on her nipples, her face red with an elusive look.

"Can... Can you brush it off ?" She mumbled.

Finn made a loud sigh and took a wet towel with his shower gel. On her breasts were written, upside down, Big breasts.

Note :
Finn : High Stamina (temp)
Karma : Big breasts (temp)