Stop: Hammer time. Armie Hammer's family has officially expanded. As reported by E! Online , the Nocturnal Animals star and wife Elizabeth Chambers have welcomed their second child. The pair, who recently celebrated daughter Harper Hammer's second birthday, are now the proud parents of a son, born January 15. Though the couple did not announce their child's name, Hammer did joke on Jimmy Kimmel Live! that they are leaning towards "Jack," or maybe Michael Charles, so "he can just go by M.C." The Social Network star knows that struggle well: his full first name is Armand — as in "Arm and Hammer." In an interview with E! News, Hammer joked that his wife, whom he wed in 2010, is basically a "professional pregnant person," stating: "She doesn't get tired. She doesn't get sick. She doesn't complain. She still exercises. She seems like she loves being pregnant and is built to be pregnant. She really enjoys it. She will tell me, 'I really like being pregnant. I feel great.'" Sounds like baby number three is in the cards — which means this couple better start thinking up some good, non-punny names ASAP.