As they pull up the restraints on the ride, they notice something jiggling on their chests as they move their arms. It's only after they've stepped out of the ride, and walked a little way that they notice.
Both Josh and Tom now sport a pair of C cup breasts, stretching out their teeshirts obscenely. Looking to each other, they see cute but kind of handsome and androgynous girl-boys.
They give into their instincts, and hands in their pockets they check themselves, to find their maleness intact between their legs. And maybe something more with a new, dampening and heating, feeling under their balls.