Submission-1◎New Wife Trained by Brother-in-Law/Future (submitter's name)
Ms. Future knew she had M tendencies but couldn't confess them to anyone, so she got married as is. A secret she intended to hide for life was accidentally discovered by her husband's brother. Moreover, the brother-in-law has an S fetish and had always been strongly attracted to Ms. Future. It didn't take much time for the two, who now shared a secret, to enter into an SM relationship.
