02/13/2012 at 06:35 PM EST
Hugh Hefner is holding hope things will work out after his son Marston Hefner was arrested for investigation of domestic violence on his live-in Playmate girlfriend Claire Sinclair.
"If they care about each other, they'll patch it up," the Playboy founder tells PEOPLE.
Marston, 21, was arrested without incident at approximately 10 p.m. Sunday and later released on $20,000 bail on the misdemeanor offense, according to Pasadena police.
According to online reports, Sinclair suffered minor injuries, and she appeared to address the matter on Twitter.
"There's two types of pain in the world – pain that hurts you, and pain that makes you stronger," she Tweeted
on Monday. "All of your positivity is giving me strength."