Sarah Michelle Gellar would be mortified if her young son watched her raunchy movie ‘Cruel Intentions’. The 46-year-old actress was “shocked” when 11-year-old Rocky told her he had used his friend’s phone to Google stuff, in case he read anything or saw anything about his mom. The 1999 romantic teen drama is considered a cult classic and contains a memorable moment when Sarah’s private school student character Kathryn Merteuil kisses Selma Blair’s freshman alter ego Cecile Caldwell, a scene which earned the pair the Best Kiss prize at the 2000 MTV Movie Awards. Sarah – who also has 14-year-old…