Horyn tweeted Friday morning, "Congratulations to Tom Ford and Richard Buckley on birth of their son, Alexander John Buckley Ford!"
Ford, 51, and Buckley, 64, have been together for 26 years. In May, Ford said he and Buckley wanted to have children, but realized that they'd have to do it in the near future.
"I think I'd better get busy soon, though, because I'd like to be able to pick them up," Ford said.
Update: A birth announcement, pictured below, that was tweeted by journalist Jim Shi claims that Alexander was born on Sept. 23.