"He fits right in with my family," Julianne Hough's pro-dancer brother Derek tells PEOPLE. "We're all kind of goofy and quirky, so it works out well."
Derek, 25, says it's Seacrest's personality that has won over his clan – not the glamorous life the TV and radio star leads.
"You know, my family's not really into private jets and things like that," Derek says. "We're very about family and love and everything like that, so [the flashy] side of [Ryan] is irrelevant for me. He's very nice and very funny. I think as long as he's a good guy and treats [Julianne] well, then I'm a happy man."
Regrettably, Dancing with the Stars fans can't expect to catch Seacrest, 35, and former ballroom competitor Julianne, 22, making a front-row appearance at one of Derek's upcoming live shows.
"Julianne's in Atlanta filming Footloose, so she can't come to any of the tapings," Derek says. "She can't come at all."