(David died of liver failure in 2017 at age 67 ... Inside '70s Teen Idol Shaun Cassidy's Return to Performing: 'Something I Never Thought I'd Do Again' (Exclusive) A father of seven kids ...

Shaun Cassidy recently swung by the Sibling Revelry ... He admitted that things changed when his father died, but the loss brought the boys back together to have a better sibling relationship.