United Kingdom, Aug. 7 -- Rob Lowe fears posting content online as his youngest son loves to roast him.

John, 30, likes to poke fun at the 62-year-old actor for scrolling through TikTok, a short-form video content platform popular with younger audiences.

Rob told E! News: "My son John Owen has made a cottage industry of roasting me online. I'm afraid to post anything. He's gonna just drag me over the coals.

"He roasts me because I enjoy TikTok. I guess it's like an old person talking about Facebook. He's definitely on me, 'Hey, dad, are you on are you on TikTok right now?'"

The St. Elmo's Fire star has John, and Matthew, 33, with his 65-year-old wife, former make-up artist Sheryl Berkoff, and he likes to watch his sons build their fut...