Harry, 22, was rumoured to have had a fling with Lohan after they appeared together in Just My Luck.
Speaking to heat magazine, Harry admits he hasn't heard from the Hollywood actress recently and of her lesbian relationship with Samantha Ronson he said: "I must have put her off guys."
Adding: "Whatever she gets up to is her own business."
Lead singer Tom Fletcher, also 22, admits he's more of a homely type. He lives with long-term girlfriend Giovanna, and says: "I enjoy cooking. If I get the weekend off, I like to cook."
He added: "I knitted two scarves for the winter. I sit in front of the TV with a glass of wine and my knitting. I'm such a woman."
Read the full story in Heat, on sale now.