Another D? You can’t keep getting grades like this, Lew.” His girlfriend was worried about him. It was only the second week of the semester, but things weren’t looking good for him. The couple sat in their college’s food court after their Friday classes. They had both planned their schedules to be done around noon on Friday, giving them the whole afternoon free.

“Can’t you, like, cast a spell to make me smarter or something? What’s the point of being a witch if you can’t do stuff like that?” He complained.

Jaime gave him a look. “I’ve already told you things of that nature are… dangerous. Unpredictable.” He was about to say something, but Jaime stopped him. “Tell you what. I can’t make you smarter, but I think I just had an idea to… motivate you. I’ll have to take a few days to figure it out, and make sure it’s doable, but I promise you’ll like it.” She took his hand in hers to reassure him.
“Trust me, okay babe?”

Lewis took a deep breath. “Alright, Jaime. I love you, I know you want to help me. Don’t keep me waiting too long though, please,” he said, showing her a smirk.

The following Sunday night, Jaime and Lewis were spending time in her dorm, cuddling on her bed. Jaime was the little spoon. One of his hands cupped a breast as they lay in silence. “Do you want to know what my motivation for you is?” she asked.

“Of course.”

Jaime spun to face him. “Well… I know you’re a boob guy. What if your grades made my boobs bigger? The better you do, the bigger I get. The worse you do…” she let him fill in the rest.

“I think that could be fun,” he said. “And sexy.”

She chuckled. “Well, if you want your cute little girlfriend to be an ultra-sexy tit-goddess, you’ve gotta start studying, mister.”

“I will, I will. Don’t want you to be flat, after all. How will it work? The spell.”

“I’ll make it so the growth happens when you show me the test. Don’t wanna bust out of any shirts in the middle of class.”

“Fair enough. Better start buying more bras, hun.”

“Fuck that,” she cursed. “They’re expensive. I’ll just magic them up different sizes. I’ll cast the spell after you leave tonight, so starting tomorrow, my boobs depend on your grades.”

The next morning, Jaime met up with Lewis for a late breakfast/early lunch kind of thing in between their classes. Sitting at their table, Lewis surreptitiously passed a piece of paper towards her. Looking down, she saw it was a graded test he must’ve received that day. Scanning it, she found the grade- 100. Her eyes widened as she felt her chest bulge, rapidly putting pressure on her bra. The top button of her blouse popped off as she grew three cup sizes in a few seconds, her newly enlarged breasts overwhelming her bra. She glared at him. “Lewis, I want to see these in one of our dorms, not in public. What if my shirt burst off entirely?”

He smiled a mischievous kind of smile. “Would that be so bad?”

“Maybe not for you, but I would not enjoy it.”

His smile faded. “I’m sorry, babe. Won’t happen again. Promise.” He put the test back in his bag.

“What subject was that, anyway?”

“Physics.”

“So the only thing you’re good at it,” she smirked.

He laughed. “Basically.”

-

A few weeks later, the effect of Jaime’s spell was beginning to be apparent- the formerly averagely-endowed student was now hefting around breasts the size of her head. She was the secret talk of the campus; the student body was—behind her back—abuzz with talk of the girl who had grown from a B into who-knows-what-size in a matter of weeks.
Inside her dorm, Jaime and Lewis dropped their backpacks on the floor and she flopped onto her bed. Lewis fished around in his bag for a test from that day. Pulling it out, he handed it to his girlfriend.

“A 92 in history? Not bad,” she said, placing the test next to her and unhooking her bra. She waited a few seconds and… nothing happened. She didn’t grow. “What’s going on? I should be bulging up another couple inches from that.”

Lewis looked around sheepishly, avoiding eye contact with her. “Dunno,” he mumbled.

She scrunched her eyebrows looking at him. “There’s another grade, isn’t there? One you got back earlier? These things have to take place chronologically, hun.”

His shoulders slumped, he handed Jaime the other grade. It was crumpled, and clearly had been stuffed in the bottom of his backpack. Unraveling it, Jaime understood why. “Oh boy,” she said. “Here we go.”

Momentarily, Jaime’s chest started to shrink down from her huge size. Smaller and smaller they shrank, until after a few seconds Jaime was completely flat-chested, with no definition whatsoever. Then, the second test took effect, and she grew a few inches, her flat chest bulging into orange-sized breasts.

“You can’t hide bad grades from me, Lew. I know this,” she gestured to her much smaller boobs, “was not something you wanted, but the magic knows what grades you’ve gotten.”

He sighed. “You’re right, of course. It was dumb to hope I could outsmart your spell anyway,” Lewis said, pouting.

“I’m gonna have to cast a reality spell for this- people will think there’s something wrong with me with my tits shrinking this much. But look on the bright side, babe, now you can experience me growing huge all over again.”

-

The second week of May, Jaime was confused. For a while, Lewis had been proud to show her his steadily improving grades. She was nearly back to her previous record size, but then he had stopped altogether. Jaime hoped he wasn’t trying to circumvent a bad grade again- he wasn’t that absentminded to forget how well that would work out. Next week was finals week, and Jaime headed back to her dorm to start studying. She’d have to collect Lewis on her way- boobs or not, she wasn’t going to let her boyfriend not study for finals. She moved to unlock her door, and was slightly alarmed to find it open. She pushed the door and entered her room to find Lewis grinning like a Cheshire cat. She put down her bag as he handed her a stack of papers.

She eyed him curiously. “What’s this?”

“A lot of grades… a lot of growth,” he said giddily.

“Oh geez, alright. Let me get ready, then.” Jaime took off her shirt and bra. Picking up the stack of papers again, she flipped through them, looking at the grades. There were plenty of A’s and B’s, with a dash of 100s added in—all physics, she was sure—with only the occasional C, and no D’s or worse at all.

“I’ve got an A in all my classes now.” She smiled and congratulated him as she felt the growth start, her melon-sized breasts bulging rapidly. Before their eyes, Jaime’s chest surged forward, reaching and surpassing her old record quickly. They kept growing from the huge number of grades Lewis had been gathering, the end of her growth nowhere in sight.

Jaime was beginning to be weighed down by her boobs, and she decided to sit on the floor as she grew, her massive tits reaching her thighs, her pale skin being warmed by the blooming flesh. “It feels so good as they grow, hun,” she moaned. Jaime started to gently massage her growing breasts, closing her eyes and enjoying the sensations coming from them. The masses swelled wider than her shoulders, wider than her hips, her nipples reaching out further and further in front of her.

Soon, Lewis could barely see much of his girlfriend beyond her head and her tits as they continued to grow and grow. He had no idea he had enough grades stored to cause this amount of growth- but he wasn’t going to complain. He had wanted to make Jaime an “ultra-sexy tit-goddess” as she had said at the beginning of the semester, and that’s just what she was beginning to look like. She was clearly really enjoying the growth, she was moaning louder and louder as she got bustier, her hands not stopping playing with her boobs. He knelt down in front of her prodigious bust and gave her nipples a quick squeeze, eager to join in on the fun. Jaime climaxed nearly instantly, the crotch of her shorts showing a damp spot. A few more seconds, and it seemed the growth was slowing down.
Jaime’s eyes flitted open and observed the sea of breast in front of her. “Geez, you weren’t kidding when you said a lot of growth,” she mused. “I’m gonna need your help to cast a few spells. I can’t exactly get up with these things weighing me down.” She saw the expression on Lewis’ face as she said that. “I know, you’re crushed. Well, I’m about to be by these boobs if we don’t get started. I’m going to need to cast a few spells—at least three—but I’ll only need help with the first two. First, I need to magic these breasts lighter so I can move around. Second, I need to change reality again so everyone thinks I naturally grew these. I’ll need a few things from your dorm…”

-

Now back home, Jaime waited eagerly for Lewis to arrive. They didn’t get to see each other as often during the summer, since they were farther than a two minute walk away. She saw him park his car in the street and wobbled her way to her front door, her beach ball-sized boobs barely contained by the bra she wore- even magic had its limits, and her enlarging spell couldn’t make her bra exactly the right size, but she managed. At least her tits didn’t immobilize her now. She smiled, thinking of the new cause of growth she had secretly cast on herself and Lewis. Today was going to be a lot of fun…