The Stepmother 5: Her New Son (2011)

Beautiful blonde Tanya Tate is all set to marry handsome divorcee Dale DaBone and move in with her teenage son and his pregnant fiancée. But Dale's ex-wife Magdalene is still bitter about the divorce - and about the new sexy blonde taking her place. Enraged and vengeful, Magdalene sets her sights on Tanya's son Seth, and they begin a torrid affair. When Tanya discovers evidence of their trysts, the busty MILF decides to turn the tables - and pay a visit to Magdalene's sexy son, Xander.