"If you don't have sex at your age, your vagina will get blocked." Her brother tells her a lie, and her ignorant sister goes wild! She tells him it would be bad if her vagina got blocked, so she inserts her brother's dick without permission! Now that she knows how good it feels, she is so engrossed in her brother's piston-like movements that she doesn't notice him saying "I'm going to cum!" or "You're already cumming inside me!" She completely ignores the creampie and accelerates her hip movements without caring about the sperm overflowing!