You decide to lower on to the boys head from above and slowly engulf him. It will be fun to have somebody inside you again.
You concentrate your will and find that you are slowly falling towards the top of his head. The sound of water splashing gently as he relieves himself is all there is, he suspects nothing.
With a tiny swish you brush against his styled and crispy hair. He feels you touch him but doesnt think anything of it yet. Perfect! you think to yourself, now is the time.
You press downward and feel yourself stretch over the boys head opening at your knot to allow his head in without expelling any air. The whole action makes a squeak and a pop, and takes just a second.
The boy gasps and his hands fly up to his head where he encounters the balloon now surrounding him. He looks silly with a large inflated balloon around his head and his fingers and hands scrambling to pull it off and losing their grip, causing loud popping sounds. He yells inside the you and it you find that your thick rubber deadens the sound. Nobody can hear him.
It would be fun to engulf him more you decide, and so you slowly press downward and wedge yourself between his skin and his shirt, moving your opening down over him and expanding to accomodate his broad shoulders. With a rip his shirt collar tears off as you move down, somehow you continue to inflate to accomodate the boy. You are a pretty big balloon now.
His arms are pressed at his sides as you move over his shoulders. He pulls them up and inside you, that was very helpful of him. He feels his head and finds its now free of the balloon covering it, but he is now inside a balloon from the waist up.
Tearing his shirt clean off you stop at his waist for a moment to decide what to do next.