Sonya Curry -- Steph and Seth Curry's mom -- says estranged husband Dell Curry cheated on her with different women while married ... and she had no choice but to divorce the ex-NBA star.
But Dell's telling a different story ... saying Sonya cheated during the relationship.
TMZ Sports broke the news ... 55-year-old Sonya filed for divorce on June 14 in North Carolina, citing Dell's "marital misconduct."
Dell responded with a court filing of his own, accusing Sonya of "acts of illicit sexual misconduct" prior to their separation, and then lying about the alleged incidents.