A source told E! News that there are no hard feelings between the former couple and explained: "I think it just fizzled."
The blonde beauty was first spotted on a dinner date with the actor in November and were accompanied by her famous father and Jon Hamm following the premiere of Sean's film, 'The Secret Life of Walter Mitty.'
But the duo only went public with their relationship when Dylan brought Steven as her date to her father's Help Haiti Home Gala in Los Angeles last month.
The blonde beauty, who recently landed a fashion campaign with Gap, came to public attention in September when she was romantically linked with 'Twilight' hunk Robert Pattinson.
But an insider insisted her romance with the 27-year-old British actor was merely a fling, saying: "Dylan is a fun chick, whatever she had with Pattinson was very brief if at all."