It's a shirt. It's a dress.

Believe there's nothing sexier than a woman in a man's shirt? Designers agree, offering shirtdresses of all stripes for spring. The latest button-ups borrow from the boys as well as TV moms June Cleaver and Donna Reed.

While Teri Jon channels those '50s icons in a navy silk shantung full-skirted version, Reiss delivers '70s bohemia with ruffled floral chiffon and Michael Kors '90s minimalism with sheaths. More literal are Levi's cargo-pocketed plaid and Thomas Pink's white-collar frocks - the last with a matching belt worn as a manly necktie.

“Shirtdresses are easy one-piece dressing and quick fixes for any event,” says Tracy Taylor, an editor at Net-a-Porter. “Whatever you do, don't take them too seriously. No pearls, pumps or sparkle. It's casual, not secretary sexy.”

Modernize with bangles and flats for work and espadrille sandals and cross-body bag for weekend. Add a slender leather belt for a short torso and a wider wrap for a longer one, she says. “Think ‘cool girl' — not your grandmother!”