The actor, who was the special guest at London's Heathrow airport to meet children taking part in the Dreamflight charity holiday, said: "You forget how wide the audience is when you do these things."
It's for a magazine, and you don't appreciate that once it's on Twitter it's a global thing or a national thing. Jo (Rowling) was a bit ... well, you know what her reaction was.
"My mum was worst - she had no idea until it was on the internet."
My mum's a magistrate and she was going into court and all her colleagues were going like ... have you seen this?!"
He added: "I got it (stick) from everyone.
"In the end the photographer did a wonderful job, it were nowt to do with me. And I've done it now, I don't have to do it again."
Lewis has just finished filming Me Before You, in which he plays the jealous boyfriend of Game of Thrones heroine Emilia Clarke - who had some male grooming advice for her co-star.
"She recommended that I waxed my legs," he said."I saw (Olympic cycling champion) Chris Hoy do it so I thought I should do that, it's kind of the thing my character should do."
Emilia said I should just wax them, not shave them because then it's just once. I didn't in the end, I shaved them in make-up and it was awful."
- PAA
