Christina Applegate and Lee Grivas 

This is some sad news.

Christina Applegate’s on-again, off-again boyfriend, 26-year-old Lee Grivas, was found dead in his apartment.

The 36-year-old Samantha Who? star is “absolutely devastated over the sudden loss,” said an insider.

Grivas — a fisherman, skateboarder and aspiring photographer — died July 1.

An official cause of death has not been issued, pending toxicology tests. The death was reported as a possible accident or suicide. There were no signs of trauma.

Applegate and Grivas were not dating at the time of his death.

The former Married.. With Children star met Grivas in 2006 while she was performing in the Broadway musical Sweet Charity.

“He was a really nice guy but also very sad,” the source says.