KC and Cindy are big on details, the more details they give, the better chance they have of convincing the listener they just heard or remembered wrong. Notice there was no explanation about Jeff being a different Jeff. Just details. Like science. Something for them to manipulate.
Here's my theory about Jeff, for what it's worth! :crazy:
If it is true that Cindy is all about appearance, as much as she loves Caylee, KC's unwed pregnancy was a blow to how Cindy wants her family viewed by the (her) world. Which is probably why Cindy was blind to the pregnancy while it was was completely obvious to everyone else.
Cindy's hatred for Jesse started when he insisted on the paternity test, it exploded in Cindy's head when it came back proving Jesse wasn't Caylee's father, their engagement didn't cool Cindy's anger in the least. Every time she saw him she saw the results of the paternity test that he insisted on taking, it was all his fault and till the end of time Jesse can never make up for the embarrassment to her family. Cindy had no problem with KC & Jes breaking their engagement, KC and Caylee deserve better. (In Cindy's mind)
KC could never have been honest with Cindy about her "dating" practices, in Cindy's mind KC didn't need to be dating, she had a toddler who needed her mommy. If a good husband dropped out of the sky to make a nice little family better yet. Enter Jeff and his son Zack. A young man raising his son alone was heaven sent. The long distance relationship was OK with Cindy, it slowed things down and kept Caylee home with Cindy where she belonged for that much longer, while KC and Jeff figured things out.
Having Jeff in Jville worked for KC because it gave her someplace "respectable" to go with or without Caylee that Cindy never questioned, anytime she wanted to spend a couple days with friends. Jeff's mom was a built in babysitter and Zack was a built in playmate for Caylee's enjoyment. In reality we know KC didn't worry about playmates or babysitters for Caylee, Caylee got dragged where mommy wanted to go. Caylee stayed where her mommy told her to stay.
Cindy probably gave KC more leeway to hang out with girlfriends while she and Jeff were "an item" too. Since KC had this nice respectable boyfriend, if she went out with the girls, there would be "nothing funny going on" for Cindy to worry about.
Eventually it became more effort for KC than it was worth, with Cindy setting up BBQ's, dessert nites and such, so she could get to know Jeff and Zack. After a few months KC told her it was over. My guess is KC still pulled Jeff out of mothballs occasionally, when KC wanted to do something without any hassles from Cindy.
Jeff was nothing more than an extension of Zany the nanny. He was a picture of how Cindy thought KC should live her life. While in reality he was the rose colored glasses KC gave to Cindy so she could go out and live the life she wanted. Any discrepancies in KC's stories are easily over looked by Cindy, who only see's what she wants to see anyway.