In the past you weren't really thinking much about trying to steal your sister's breasts for your perverted little test, but with them being that large and lactating you wondered something. You tapped on your sister's left breast a bit and managed to select only the breast and not the nipple. you then looked on your body for something to trade and decided it would be interesting to tap your left ball sack.
taking off your pants your sister complained "Woah Woah! what are you doing?!?"
you said "Just wondering something about t hat lactation condition of yours"
with your pants down you now tap your left ball sack and then quickly tap your right balls sack and your sister's right breast. Immediately you felt a large weight pulling down on your crotch and saw two basketballs made a flesh hanging down from where your balls used to be. you went and squeezed the orbs with your right hand and found it pleasurable instead of creating pain like they used too, but you didn't notice one thing. As you were squeezing your dick had gotten harder and you had spewed a large amount of milk. You then look to your sister and saw two nipples on what used to be your balls, but something interesting was going on. The balls seemed to be expanding, already they are about the size of apples. Looking at your boob balls you notice that they weren't growing or shrinking and that they didn't feel like they had any pressure to them. However your sister's chest was growing and you noticed that her nipples were dripping what you assumed was pre-cum.
Erin cupped her balls and winced in pain as she put too much pressure on them and said "this is worse... this is a lot worse..." At this point your old balls had swelled to the size of soccer balls and soon to be basketballs.
you suggest "why not just tweak your nipples?"
Your sister glared at you as if to say "I can't believe you expect me to do this." and then went to tweaking her nipples. It felt amazing to her and soon her nipples let out a large amount of her load.
Looking at the ground you see a large amount of bodily fluids on the ground and said "We should probably find something to clean up this mess." You look around and saw what looked like some special roomba and activated it and the thing started cleaning up the mess as if it were made to clean up bodily fluids... considering your father's inventions it probably was specifically made for that purpose.
Your sister asked "Can I please have my breasts back now? As much as I like these giant scrotum that hurt if you apply pressure i'd really prefer my nice soft and sensitive breasts now."
"sure sure... give me a moment." you tapped your breasts away after a second quick squeezing and discharge. You notice that your balls were about the same size as your sister's oversized breasts and... they were still the same size. you continued "I suppose I should also find a solution to these things... while it may be nice to have them large they aren't functional." paying more attention it seems as if the pole of your dick itself is growing a little. However it's time to look for something that may solve your situation. What do you try to do?