"She said she wasn't really into it at the time," the insider shared with Us at the premiere of MacFarlane's big-screen debut, Ted. "[Then] she was ready for it to be more serious and make it more public, and he didn't want to."
The reason the comedian, 39, is hoping to keep their relationship under wraps?
"He doesn't want to distract from Ted," the source explained of the first-time filmmaker. "This [movie] is his baby and he doesn't want to take attention away from it." (When reached for comment, a rep for MacFarlane insisted to Us that he and Knapp are not dating.)
Still, inside their circle of friends, their status as a former item is an open secret. "Alexis said people in the industry know about it," the source said. "She really liked him and wants it to be official."