Ted, who was Mary Jo's long-time boyfriend, disappeared from the series.

What happened with him and Mary Jo that ended the relationship? Was it the baby?

I just can't remember...

You mean J.D. Shackleford. Ted was her ex-husband.

I believe that J.D. got a new job and moved away. I feel like he moved to Philadelphia or something.

I don't think it had anything to do with the baby, because he came back for an episode when Mary-Jo decided to have another baby, and eventually she decided it wasn't right to use him for the purpose of making a baby, and JD felt he wouldn't be able to have a child and not raise it.

Ted Shackelford played Gary Ewing on Knots Landing. Honest mistake!:D People used to confuse Tom Bosley(Happy Days) with David Doyle(Charlie's Angels) because Doyle's name on Charlie's Angels was Bosley.:lol:

The end of the relationship between Mary Jo Shively and J.D. Shackelford (Richard Gilliland) was a gradual process marked by a formal breakup in Season 3 and a final departure in Season 5.

The Initial Breakup: Their primary relationship ended in the Season 3 episode "Mr. Meal Ticket." After J.D. lost his job as a talent scout for the Atlanta Braves, he moved in with Mary Jo. Mary Jo became concerned that he was becoming too comfortable being unemployed and feared he would become permanently dependent on her. This led to a major fight, and Mary Jo asked him to leave.

The Casual Dating Phase: In the subsequent episode, "The Engagement," Mary Jo officially announces to the group that they have broken up and that she is looking forward to entering the casual dating world again.

The Cincinnati Move: Though they remained on friendly terms and J.D. appeared occasionally afterward, the final nail in the coffin was his career. He was eventually forced to take a job in Cincinnati, which effectively ended any chance of a full reconciliation.

The Baby Issue: While you remembered a baby being involved, it wasn't the cause of the breakup, but rather a final attempt to reconnect. In Season 5, when Mary Jo decided she wanted another child through artificial insemination, she approached J.D. to be the donor. He eventually declined, as he felt he couldn't be a "father at a distance".

Following J.D.'s departure, Mary Jo's love life remained famously "unlucky," as she navigated several short-lived and often disastrous dates for the remainder of the series.