The two nineteen year olds lying in bed together had never done something like this before. Both had been shy in high school and met each other in college. They had hit it off almost immediately, and now here they were, the summer break after their freshman year, in bed together, naked.

“Are you ready, Joe? I am,” Anna said. “I think.”

“I am, babe,” he replied. “Let’s get going.”

“I’ll get you going,” she said, smirking, as she slowly moved down his body, taking his stiffening cock into her hand. Stroking it, she decided to do something she had never tried before. Leaning down, she took his hard manhood into her mouth and bobbing her head up and down. To both their surprise, he came in only a few seconds.

It was so quick and forceful that Anna didn’t even think about her reaction, she just swallowed.

“Whoops,” Joe said. “Sorry, honey.”

“It’s okay, I- woah. Wooaaahhh.”

“What’s wrong? Anna? Are you okay?”

“All of a sudden I just feel… strange. Not necessarily bad, just… different.” In the dim light of her bedroom, neither of them noticed her small breasts start to slowly swell. Anna had always been embarrassed by having small boobs, subconsciously wishing her A cups would grow into something big, or maybe even something huge.

Anna adjusted her sitting position and felt a new sensation- her breasts jiggling. Immediately, her hands flew up to her chest, and she was amazed to feel much larger boobs than she was used to. These were at least C cups, nearly filling her hands.

“Oh my god, Joe, this is amazing!” She grabbed one of his hands and brought it up to her growing breasts.

“What is? What’s going- oh! Your boobs! They’re growing?”

“Yes! They’re getting so big! Feel them!” Joe’s large hands cupped her swelling tits as they grew past a D cup, rivaling softballs for size. Quickly they grew, filling his large hands.

“Keep playing with them Joe, it feels so good.” Her nipples hardened as he groped her swelling chest. He felt himself get hard as his beautiful girlfriend quickly grew curvier. Larger and larger her breasts grew, overwhelming his hands, now looking like honeydew melons. The growth slowly came to a halt, leaving Anna with breasts larger than she had seen in real life, H cups at least. His hands slowly trailed down to her hips as she moved to straddle him.

“I think I need you, Joe. Right now.” Anna grabbed his cock more forcefully this time, his already hard manhood surprising her because it was larger than a few minutes ago. “Oh my- Joe- you grew too! Look at this thing!” Joe’s dick now was much larger than his original six inches; now it was a behemoth nearly ten inches long and two inches thick.

He stared at himself incredulously. “What is happening to us?”

“I don’t know,” Anna said, positioning herself over his huge member, “And right now, I don’t care.” She lowered herself, pushing herself down on his cock, stretching herself as the first penis to ever enter her was almost inhumanly large. She bottomed herself out and began moving back up, milking his cock for all it was worth. Both of them started moaning in pleasure, Joe’s hands returning to Anna’s huge breasts. He gently played with them and then suddenly pinched her big nipples, sending a shock through Anna’s body, the electric feeling making her climax as she rode him.

“God, Joe, you’re so… fucking… big,” she panted, “It’s so good, keep playing with my big tits.”
Being that this was both of their first times, Joe couldn’t last as long as he would have wanted to, and as Anna lowered herself again, taking the most of him into her as she ever had, he climaxed, spouting inside of her, his huge cock pumping his cum into her. Joe’s balls had grown as well, ensuring that there was a large amount of semen entering Anna. Luckily for her, unknown to her, she could only get pregnant if she wanted to. She didn’t want to now- in fact, all she wanted right now was bigger boobs.

Her wish was granted as the power of Joe’s ejaculate was shown again. As she rested on top of him, her boobs again started to grow, enlarging from melon sized past head sized, quickly passing anything Anna could pin a bra size on.

“Oh my god, it’s happening again, my boobs are getting so fucking huge,” Anna said, excited.
Joe just stared as her breasts grew again, growing past volleyball size, her huge nipples keeping pace, looking like bottle caps now, constantly getting longer and thicker.

“It feels so good… please suck on my nipples, babe,” Anna moaned. Joe obliged, gently pulling her down until her swelling tits brought a huge nipple to his mouth. He latched onto it and sucked.
Anna suddenly felt a pop in the breast her lover was sucking on, followed by the sensation of something flowing out of her nipple. She nearly climaxed again from the feeling of liquid being released from her breast.

“I’m… lactating?” she moaned, looking down at Joe, who temporarily released her nipple from his mouth.

“You are, babe, your milk tastes amazing, too.” Quickly he put her growing nipple back in his mouth. Her breasts kept growing as Joe sucked milk out of one of her breasts. He brought a free hand up to her other nipple and started pulling on it, trying to get her to express from that boob as well. He was successful, and her milk started to flow out onto her mattress, soaking into her sheets. The feeling of lactating from both of her huge, growing tits was too much for her, and she began climaxing over and over again.

Finally, Joe ceased his work on her nipples as he was full of her creamy milk. She sat up, trying not to smother her boyfriend with her still-growing breasts. They were getting as huge as she always wanted them when the growth slowly came to a stop.

Anna sat back and ogled her huge tits. They nearly rested on Joe’s chest as she sat up, hanging down past her hips. They flowed down her torso, covering her with a foot and a half of breast at their biggest point, ending with pert yet big nipples a couple inches in diameter. Anna placed her hands on the outer edges of them and was amazed to see that her tits were at least six inches wider than her narrow hips.

“These boobs are…” she started, staring at her massive frontage.

“Huge? Gigantic?” Her boyfriend suggested.

“… beautiful.” She finished. “What do you think, babe?”

“I’m of the opinion that you lactating is one of the hottest things ever.”

She smirked. “Me too.”