You are still slightly mentally off balance after realising that you're stuck with the big bust, and you still feel like a freak with them, even though you're sure everybody has them. It occurs to you that you'll be the only guy your age in the world that doesn't know about anything that has changed besides the obvious so you decide to spend some time reading up.
It takes a couple hours for you to feel sure you haven't missed anything important, but you have discovered that in this new world it's still inappropriate for women to go around with bare breasts, and that this applies to men as well, though topless nudity is now viewed as less severe than before and it's acceptable (briefly) in PG13 movies. You additionally discovered that in this world men who spend enough time around a woman in late pregnancy and shortly after will begin to lactate within a few weeks of the birth. On average men have smaller breasts than women, about 60% of men wear either an A or B cup and another 25% wear a C. What's surprises you is that the women with breasts smaller than a B cup are virtually non-existent, though B's are still reasonably common, it's as if almost all women who were A cups or smaller changed to have something mostly in the range of B to C fairly evenly.
You had also stumbled across some surveys that asked people what they found physically attractive in a partner. You discover that nothing has really changed about what men like, some like big boobs, some like small ones, though small means a slightly different thing now. Much more interesting is women's responses, though aside from boobs not much seems different, women seem to be fairly divided on the subject of what makes a man attractive, particularly with boobs with a 20% women preferring flat chested men, 55% of women having little to no size preference, and 25% liking larger men. The surveys did make it clear that a significant portion of women from the no preference group weren't terribly interested in their partner's chest at all, though an also significant portion of women from all the groups reported that they liked their partner's chest, and enjoyed feeling them up as much most men enjoy feeling up a woman.
You wonder about your girlfriend who prior to your meddling with the world was quite flat-chested, certainly enough that she would be bigger now, what size did she get? You hunt around your dorm room trying to remember where the spare bra that she left there is. After several minutes digging through your clothes you find it and hold it up, it looks big, you check the size tag and find that it says 36DD. You imagine what she looks like now, her usual curvy self, but with the size up to now to match and balance her wide hips. You like the image in your mind, she had a figure you liked before, now it's much better.
You wonder how she feels about the fact that you're boobs are bigger than hers, though to her it's always been this way, this prompts you to wonder if she's into boobs, or if she doesn't particularly care. Your earlier experience playing with them yourself leads you to hope that she likes doing that to you.
All this though of your girlfriend and her boobs and her playing with your boobs has been getting you turned on slightly. You wonder what it would be like to give your girlfriend a hug and feel her breasts push against yours, if you're fucking her in missionary will your boobs rub against hers? What will that feel like? You feel yourself starting to get hard.
Your mind wanders hornily, and you begin to wonder what it's like to have sex as a woman, would your girlfriend would be willing to try things out if you used the light to swap your genitalia? You snap back to reality, slightly weirded out by that line of thought, but the idea lingers. It wouldn't be so strange she would still look the same everywhere else, and as far she knows so would you.
You think for a moment about going back to the way you were before, your boobs are a fair bit bigger than you'd like to be stuck with permanently but aside from the size you're not entirely opposed to having them, you'd something closer to D cups, but you do seem to be stuck.
You skim the instructions that you got with the light, it seems pretty clear that you should be able to make changes both you and your girlfriend are aware of if you both hold it at the same time, but you find nothing that indicates a way you could undo what you've done. But you make a last ditch attempt to reduce them by setting the light at it's brightest blue setting, hoping the imbalance in normal size between the sexes will let you shrink them.
For a moment nothing happens, then it works! Your chest shrinks a bit, only down to a DD, but it's enough of a difference for you, they're quite a bit lighter and more comfortable to have than before, even just a cups size or two makes a difference. They'll still be bigger than your girlfriend's since cup sizes are proportional to body size.
You glance at the clock it's early in the evening you wonder if your girlfriend is busy tonight, and how she would react to the flashlight's power.