Crystal Harris Visited Hugh Hefner on Father's Day
06/20/2011 AT 06:30 PM EDT
"Crystal came by to see how I've been doing," Hefner, 85, Tweeted on Sunday. "We remain close friends."
Harris, 25, who enjoyed poolside time with fellow blonde Heidi Montag over the weekend, didn't show up empty-handed.
"Crystal brought Charlie back because she thinks he's happier here," the Playboy mogul wrote of the doggie the couple once shared. "I appreciate it, because I really missed him."