Louis Tomlinson, of boy band sensation "One Direction" takes his girlfriend out for coffee and a walk around Toronto on May 30, 2012. Credit: O'Neill/White/INFphoto.com

It's hard to pinpoint "One Thing" Louis Tomlinson loves about model Eleanor Calder, his girlfriend of seven months. "I'm a one-woman man with Eleanor,"  Tomlinson, 20, says in Us Weekly's One Direction special issue (out now). "I'm a very loyal boyfriend."

The English pop star and his Hollister model girlfriend were spotted strolling hand-in-hand through the streets of Toronto May 30. "I love him as a person," Calder has said, "not as a member of the band."

Though One Direction is taking the world by storm, Tomlinson still prefers low-key dates to extravagant outings. "I'm a bit old-fashioned, and I like the idea of going to the cinema and then an Italian restaurant," he admits.

So what does Tomlinson look for in a significant other? "If they're tidy, that would be good -- because I'm not!"

Tomlinson met Calder, a sophomore at the University of Manchester, through bestie and bandmate Harry Styles, 18. Since then, it's been nothing but bliss for Tomlinson. "I'm a bit of a joker," he tells Us. "I can be a romantic -- but not too sickly."

For more on Tomlinson and his European bandmates, pick up Us Weekly's One Direction special issue, available now!