It had been a rough few years since the divorce and since I really didn't really have a choice in the matter, I stayed with Dad until I finished my senior year. I couldn't wait to go off to college and I picked a small uni several states away to put some distance between me and the constant bitterness that surrounded that house. Two years in money got tight and the whole pandemic bullshit drove me back home to take my courses online and get a job locally. Little did I know, that was the beginning of the best part of my life, even if it didn't seem that way.

Dad had finally gotten a better job as a truck driver and he seemed to be happy seeing the country and making lots of money, and one day he came home with someone after a weeks long coastal turn. She was younger than him, but only by four or five years. When she introduced herself, hand outstretched, I noticed one thing in particular and I tried not to stare. She was only about five feet tall, a bit thick in the thighs and midsection, but she was incredibly endowed in the chest. "Hi, I'm Fay and..." she nervously looked over her shoulder to my Dad, "I'm your new step mother." I shook her hand and gave a very surprised congratulations and then hugged her. The feeling of her huge chest against my waist was exciting, but I quickly pushed that idea from my mind. She was family now, even if she was an unwanted replacement for my mother who had left for the deep south and rarely texted or anything.

The weeks went by and falling into a routine gave us all some structure. Dad would take her with him on occasion, but she said the travel wasn't much to her liking, so more often she would stay home and tend to the house. I found myself becoming protective of her and she clearly doted on me with sandwiches or cookies offered at odd hours, but one Monday as Dad left for a two week turn, things escalated. It was harmless, or so I thought. We would bump into each other in the kitchen and laugh, scare each other on accident late at night going to the bathroom, share a meal and watch tv together on the sofa and when she would laugh, her hand would rest on my thigh a bit longer than it should have. And one night she walked in on me taking care of myself with a plate of cookies in hand. She dropped them and embarrassingly apologized profusely, looking at the floor and picking up her spoiled baked goods. "I'll knock next time, sorry sorry sorry!" I laughed it off and finished up, but as I went to bed I wondered if she liked what she saw....

I'll stop there, I don't want to dictate too too much in this story. In short, I want a scene where our flirtations come to a head, and I use my step mom's tits and mouth to please myself, but in doing so there is an unforseen byproduct. Either immediately or over a few hours, her tits are going to grow larger than her already prodigious size either by getting cum/precum on her breasts, and/or by swallowing my load. This will also cause extreme lactation in a short while, that I will of course help her relieve, and in doing so gain several inches, maybe even a foot or more through the feeding. I want our appendages to get bigger and bigger, eventually becoming outrageously huge. The one thing I would like is some dedication from her to always try to get bigger so she can hold my ever growing cock between her soft, massive tits and please it and the gargantuan balls pulsing beneath. So, if expansion is your thing, let's grow huge together. Or massive. I really don't have any size limits. Only limits are illegal stuff and beast. Please dm with a starting description and name for your character, unless you prefer using the one I provided in the prompt. Let's grow massive together and let's have some fun! Other kinks include deepthroat, cum bath, facials, impreg risk, anal, titfuck, handjob, nipple fuck and possibly D/s. I usually write two to four paragraphs and expect the same from my partners.