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Prenuptial coitus: Bride cuckolded during the ceremony

"I love you, sis! I'm going to cum inside you like this...!"
Kiyoharu's younger brother, Kiyoharu, indulges in fantasy pussy while peeping at his older sister, Ayaka, as she gets dressed.
One day, he wants to strip off her bra and underwear, and have sex with her,
But when Ayaka tells him that she is engaged to be married...?
Shocked, Kiyoharu runs away, unable to admit Ayaka's marriage.
But on the day of the wedding...?