Paul Daniels has told how he had a "scare" early in his career, when he discovered the girl he was kissing was still at school.
The TV magician, 74, recounted the experience on his online blog, according to reports, and said he stopped the kiss as soon as he found out the girl's age.
Daniels said in his post, which has since been removed, that the showbusiness world in the 1970s was full of "groupies".
"Did I have such a life? Yes. I would be lying if I said I didn't. Were they all over 16? OMG I hope so. Can I remember them? No," he is quoted as writing.
The Sun and Daily Mail said that Daniels described an experience which occurred when he was 30. "A mini-skirted girl was thumbing a lift. I gave her a lift and drove on into the night whilst the more-than-slightly tiddly girl moaned on about her boyfriend ignoring her in the pub that night and that she would get own back on him.
"Oh goodie for me, I thought."
He added: "I kissed her goodnight and it got a bit more passionate... Thank God it didn't get too passionate because something she said sent a shiver down my spine... she said she was still at school."
The veteran entertainer, who is married to former stage assistant Debbie McGee, 54, said: "I had her out of the car as fast as I could and I drove off with the lights off so she couldn't see my number plate!... I felt sick."
He reportedly added: "I was terrified but maybe that scare was a good thing 'cos from then on I would always talk about their jobs or whatever before anything went too far."
Writing in the wake of the Jimmy Savile scandal, the newspapers reported Daniels as saying that the late entertainer was "undoubtedly a bad guy", but added: "I have been wondering if all of the accusers are for real. I can fully understand some women not wanting to talk about what happened to them, but for over 400 of them to keep quiet for 40 years seems strange."