Jennifer Morrison and Sebastian Stan are an item

Jennifer Morrison and Sebastian Stan © Josiah W/Splash News Online

Couple alert! Once Upon A Time must be a fertile breeding ground for relationships. Ginnifer Goodwin and Josh Dallas (Mary Margaret Blanchard/Snow White and David Nolan/Prince Charming) announced they were coupled up in April, and now Jennifer Morrison and Sebastian Stan (Emma Swan and Jefferson/Mad Hatter) have taken their relationship public as well.

A source tells People Magazine, "They met on set and are now exclusive. They started dating three months ago. They seem to be really happy together, but are trying to take things slow." Both lovebirds aren't new to dating a co-star. Sebastian, 28, dated Leighton Meester when starring on Gossip Girl and Jennifer, 33, was engaged to her House M.D. co-star Jesse Spencer.