Jon Gosselin is estranged from his ex-wife Kate, lost his legal battle to keep his children off TV, and now RadarOnline.com has exclusively learned that his own stepdad doesn't know how to get in touch with him.

Albert Castello is married to Jon's mother, Pamela, and lives in Pennsylvania too.

In an exclusive interview with RadarOnline.com, Castello revealed that he hasn't spoken with his stepson after Jon's public Twitter rant about the judge's decision to allow his children to remain on television.