Lorenzo Lamas and Shawna Craig Here's How She Gave Birth To My Grandson

8/17/2015 12:40 AM PDT

Lorenzo Lamas and his wife Shawna Craig answer every question anyone has about her giving birth to his grandson, and it gets real graphic.

Craig is married to Lamas, which makes her the stepmother to his daughter Shayne. Craig served as the surrogate for Shayne’s baby ... meaning Lamas' wife gave birth to her husband's grandson.

We caught grandpa and his wife leaving the Natural Birth Center & Women's Wellness in LA and asked them about the whole ordeal, which Lamas admits was traumatic.

Bonus ...Craig even gives us a play-by-play of the close call with her placenta.