Both

Alice hadn't given you any instructions, and you're far too horny to give much thought to the colour-coded pills. Without any hesitation you shove both into your mouth and swallow hard smiling manically as you reach towards your cock eagerly.

You not disappointed at all you could feel a surge of pleasure and blood rushes to your groin the heat of your loins is like a furnace and almost as soon as your hand reaches your shaft you can feel everything begin to expand. Your cock begins to lengthen growing longer and thicker with every passing moment every time you take a breath the heat and pressure begins to grow even more intense. It's not just your impressive man meat that is growing you can feel your sack swelling with semen the pressure running against your legs as the pleasure begins to overwhelm you. Your almost 15 inches now thick like a coke can your hands rubbing along either side of the impressive shaft pushing it upwards towards your...

He let out a groan, keenly aware that the flesh of your upper body was also changing. You been so focused on the pressure between your legs you hadn't even noticed how hot your nipples felt, how each one was now sitting atop a rather impressive mound of feminine flesh. You grasp your cock feeling it grow longer and thicker even now swelling with each progressive throb pushing against your equally sizeable breasts. Obviously this pill was for her and you can only feel like a passenger as you wrap your shaft in glorious breast flesh.

Alice is still barely with it and doesn't really process your transformation until your pushing almost 2 foot of cock directly against her treasure.

"Marky?" She groans a mix of excitement and fear filling her voice as you ram your enormous erection directly into her stretchy innards. You feel your massive balls slapping against something wet gasping as you realise that your breasts were not the only new addition to your body. As you for your sister up with your enormous cock you are also keenly aware of the drooling vagina crying out for attention. Your breasts are still swelling, now almost the size of your head and looking rather odd on your otherwise masculine body, but your figure out something later.

Right now you have a mad scientist between your legs and you fully intend to ream her until she squeals.