Fashion & Beauty

Jack Antonoff’s sister won’t be designing couple’s outfits for him, Lena Dunham

Don’t count on Rachel Antonoff designing any matching duds for her younger brother Jack Antonoff and his girlfriend Lena Dunham to don on the red carpet.

“I like to keep my family and personal life separate [from work]. I don’t know why, I just really do,” she said Thursday at her science fair-themed presentation at the Professional Children’s School, which featured an organ print and a dissected-frog print. “Once I become close friends with someone, I almost back off on that part. It’s just too messy. It hasn’t gotten weird [with Lena], but I think that’s because we’ve had a nice [relationship].”

Still, family influences her work. Jack, who fronts the band Bleachers and wrote for Taylor Swift’s “1989” album, got a sneak peek at Rachel’s new collection.

“He’s my main sounding board,” said Rachel.