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 Charlotte with husband Freddie Prinze Jr, 47 - told Us Weekly magazine: "A year or two ago, my son came home and said, 'Oh, so-and so has a phone and I looked something up. I was shocked. I don't need my fifth grader watching 'Cruel Intentions'."

Sarah is only letting her son get his first phone this summer and she will still be in control of what he views.

She continued: "My son will be getting his [first] phone in June. I'm appreciative of the security features and take full advantage of them.

"I control [the] websites he can be on, so I can use that as the teaching moment."

The 'An Invasion of Privacy' star also delayed her teenage daughter joining social media and made her run anything she posted by her parents first.

She said: "Charlotte was one of the last ones to get it and thought it was unfair. I explained that when your parents are public figures, there's different rules. Our rule was that she couldn't post until she ran it by us."