The superstar couple, who tied the knot in 2012, recently welcomed a third daughter into their family. This new bundle of joy joined older sisters James Reynolds, 5, Inez Reynolds, 3, in the Reynolds household.
Ripa, who also has three kids, then went on to share her theory about having three children during the Live With Kelly and Ryan chat.
"If you have the third child, have the fourth child," Ripa advised the actress. "Because triangulation in children can be bad."
"You can have my fourth child for me," Lively replied. "You're hearing it live, she's the surrogate mother for me."
And Ripa accepted the job, telling Lively, "I will be the world's oldest surrogate mom."