Your hand is still on Alex's massive arms when he starts growing right in front of you. Your first instinct is to step back, but you can't bring yourself to remove your hand from his incredible bicep. It gives off a powerful, warm feeling, and something about it seems almost… intoxicating.
Pretty soon, though, you find that if you want to keep touching your brother's arms, you'd have to stand on your tiptoes. He's already gotten nearly a foot taller than he was just a minute ago, and doesn't seem to be showing any signs of stopping. You look up, your mouth nearly quivering with a mixture of fear and astonishment. Alex is too busy enjoying the pleasurable growing sensation to notice you, though.
"Ohh, yeah!" he moans, as he flexes his arm and chest muscles, making his pecs dance a little on his body. "This feels so good!" He closes his eyes, and starts to move his tongue across his lips in a slow, sultry manner.
You are so entranced by this that you barely notice the sound of something ripping, but your attention is grabbed when Alex's board shorts finally tear off and float to the ground. This caused Alex's equally-impressive cock, now eye level with you, to burst forth from its cotton prison, slapping you in the face as it did. A strong musk fills your nostrils - one that is unique, and oddly arousing. Your own hard-on begins to press against the fabric of your pants, and you feel an intense desire to reach out and touch it.
Alex notices you staring at his cock, and smiles down at you, his face looming over you in an imposing but comforting manner. "Go ahead," he says, "I know you want to as much as I do."
You take a moment to consider all this, unsure of what to do. Gulping, you finally decide to …