Kristen Bell and Dax Shepherd often open up about their longtime relationship both before they were married and since - but it turns out there's still plenty more their fans don't know. The dad-of-two made a reveal on his Armchair Expert podcast and detailed a romance he had pre-Kristen with a very famous celebrity. MORE: Kristen Bell debuts dramatic new look in knee-high bootsDax confessed that he dated Ashley Olsen and he had nothing but great things to say about the star. WATCH: Kristen Bell and Dax Shepherd's spacious living room inside Hollywood home The news came about while he was chatting about Ashley's clothing line The Row, which she founded with her twin sister Mary-Kate Olsen.He then said: "She's just the most wonderful person. She's fantastic," and admitted he dated her 15 or 16 years ago. LOOK: Kristen Bell looks gorgeous in daring red leather suitREAD: Mary-Kate and Ashley Olsen break silence after Bog Saget's death At the time she was working on her clothing line and he added that "she was putting all her energy and focus into launching that in a big way".