In a cramped attic hideaway, a curious teen sibling duo, forbidden by their stern father, explore their burgeoning desires. The girl, innocent yet curious, watches her brother's cock grow hard in his tight jeans. She tentatively touches it, then, emboldened by his groan, unzips him and takes it in her mouth. He teaches her how to suck him, how to make him cum, then returns the favor, making her first time a sweet, sticky mess of shared pleasure and taboo.