Rod Stewart had the talk with his teenage son, but it didn’t go as expected for the father of eight."I have to be several different fathers because of the different age groups of my kids," father-of-eight Rod Stewart tells PEOPLE 

The 76-year-old Tears of Hercules musician tells PEOPLE that he had a funny moment with Alastair, who turns 16 this month, when he sat him down to talk about sex.

“My 15-year-old is dating girls, so I had to give him a sex lesson. I just told him what he should and shouldn’t do, but he’s on top of it. He was like, ‘Dad, I’ve got the internet. I know everything,’ ” says Stewart.

Stewart shares two sons, Alastair and Aiden, 10, with wife Penny Lancaster, whom he wed in 2007. Additionally, Stewart has daughter Sarah, 58, whom he and ex-girlfriend Susannah Boffey placed for adoption as teens; son Sean, 41, and daughter Kimberly, 42, with ex-wife Alana Stewart; daughter Ruby, 34, with ex-girlfriend Kelly Emberg; and daughter Renee, 29, and Liam, 27, with ex-wife Rachel Hunter.

“I have to be several different fathers because of the different age groups of my kids,” explains Stewart. “You really have to treat all of them as individuals with individual problems.”

The key to his 14-year marriage with Lancaster, Stewart tells PEOPLE, is intimacy: “I’m not talking about sex, but a kiss and a cuddle and a hold. Penny and I do that every morning. We hug each other — sometimes in bed, sometimes out of bed, all throughout the day. It’s a wonderful relationship. Lucky geezer, aren’t I?”

“I couldn’t ask for anything better,” he adds. “What makes me happiest now is seeing all my kids and my wife with big smiles on their faces.”

Original Article: Rod Stewart Shares His 15-Year-old Son’s Response to Sex Lesson: ‘Dad, I’ve Got the Internet’