Harry Potter star Matthew Lewis was getting so much attention from his sexy Attitude cover shoot last month that he had to turn his phone off.

"The reaction was crazy…it was just a bit weird. It's all nice stuff being said, I can't complain about it, it's very flattering. It's just weird to have people talking about that," he told the Evening Standard.

Related: Matthew Lewis Just Got 10 Times Hotter In Behind-The-Scenes Footage From His Attitude Shoot

The 25-year-old actor did, however, leave his phone on long enough to receive a personal text message from J.K. Rowling, who tweeted him to "put some clothes on" after the sexy shirtless shots went viral:

.@Mattdavelewis Not as bad as watching Dan in Equus, but close. Warn me next time, for God's sake. https://t.co/r8EUd1GKqT

— J.K. Rowling (@jk_rowling) May 21, 2015

Lewis said Rowling texted him the next day just to assure him she was joking.

"Bless her, she messaged me the next day to say ‘you know I was joking right’ – she’s so lovely," he said. "Even now after so many years of doing this job I still forget how massive Harry Potter is and how many millions of followers J.K. Rowling has and that every little thing she says gets picked up. It’s very easy to underestimate that whole thing, so what I thought was just a bit of a thing between us that a few Harry Potter fans might see and enjoy became a huge thing."

Lewis admitted the photos "went a little bit more high-profile" than he anticipated. The public loved them but his mother apparently did not.

"My mum, bless her, was not happy at all. My dad thought it was funny," he said. "My mum is a magistrate and she was at the court and all of her colleagues who are magistrates were coming up to her going, 'I saw your son' and she hadn’t seen it at this point."

"She knew I’d done something for a magazine. Anyway, someone showed her and she was mortified. So I got bit of earache from her. Apart from that it was great."

Lewis is adding more weight to his newly beefed-up frame to play a triathlete in his new film Me Before You. "I probably need to stop eating cake at some point," he said.