Oz Perkins -- the actor Reese Witherspoon bitch-slapped in "Legally Blonde" -- is calling it quits on his marriage after 16 years.
Oz, the son of late acting legend Anthony Perkins ... just filed for divorce from Sidney Perkins. According to the divorce petition ... he's asking the court to hold off on deciding spousal support.
Interestingly, he lists their separation date as TBD. That date would be the cutoff point for sharing their assets.
Oz and Sidney got married in 1999. They have two minor kiddos -- 11 and 7 -- and he's requesting joint custody.