Father's Day was especially joyous this year for a West Islip family after a son donated part of his liver to his dad.

Robert Meyer, 61, spent Sunday playing sports with his children and grandchildren ? and he did it with a new liver.Meyer Sr., a former NYPD officer, was diagnosed with liver cancer last November. His son, Robert Meyer Jr., stepped up to the plate and donated 60 percent of his liver. Rob says after a slew of psychiatric and medical tests, he was given the green light.

"I knew I wanted to do it for about five months," said Meyer Jr. "As soon as I found out he was sick, I volunteered before I even knew what it entailed."

The surgery occurred about a month ago. "Everything is working fine, no problem with anything," said Meyer Sr. "They said I could live another 20 to 25 years. It's good to have a 34-year-old liver because that makes your whole body respond as if you're 34 years old."