No telling yet where Li'l Jack fits in, but we're assuming some flashbacks with Richards.
LOL I know it sounds stupid, but is not like that. I don't know how to explain it. Jack cares for Liz not just to make babies. Like for example when you meet some one incredible, you say Ohh I want that man/women to be the father/mother of my child. You feel like you have found the right person, your soul-mate, and therefore you would want to have a family with him/her. Because you feel you were meant to be.
Thats just me babbling 🙂 The person that can explain that to you is not here. She does it better than me Lovely where the heck are you???????>