Why Simon Cowell Hopes His Son Eric 'Never' Comes on 'America's Got Talent' (Exclusive)

Simon Cowell is beyond proud of his son, Eric — but that doesn't mean he wants to see him on the world's biggest stage any time soon!

Speaking to PEOPLE backstage after Tuesday's America's Got Talent live show, the judge explains why he hopes his 9-year-old — who was in the audience for the season 18 qualifier round — will "never" come on the show as a contestant.

"He's a good drummer," Cowell, 63, says of his son, whom he shares with fiancée Lauren Silverman. "He really is. Thank God it wasn't violin, it was drums. And he's really good. I mean, he's in time. He's in rhythm. I keep saying to him, 'If you're good, never come on the show.'"

When asked what kind of act he and Eric would perform if they took the stage together, the judge admits he would probably "stand in the wings" while his son stole the show with his drumming skills.

"Oh God," he groans. "I dread to think... I would be, I actually don't have any performing talent whatsoever, so it would have to be him. I would just stand in the wings."

The judge also tells PEOPLE he loves seeing Eric and his friends get "excited" in the live show's audience, explaining that his son has been coming to watch the performances since he was "really young."

"He's a great barometer," Cowell shares. "I look over to look at him, 'Is he having a good time?' And he was having a really good time when he's up on his seat, excited. [It] is the best thing, because with kids, it's all unfiltered."

This isn't the first time the proud father has spoken highly of his son's budding talent. In August, he revealed to Entertainment Tonight that the 9-year-old wants to pursue a career as a drummer and "be in a rock band."

"He’s now decided he's going to audition for Britain's Got Talent," he told ET at the time. "I think he wants to be in a rock band. He loves Green Day."

“That's going to be total torture," Cowell continued, joking. "I mean, of all the things I've ever done, this will probably be the hardest, because he does play drums. [He's] going to drum and sing! I went, 'Oh God, no.'"

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Fans will find out which two viewer-voted contestants to move onto the season 18 finale when the America's Got Talent results show airs Wednesday at 8 p.m. ET on NBC.