Looks like Three’s Company is in the blood for the Ritter family as John’s son Jason bears his buns for two friends in the hot tub for the film The Education of Charlie Banks. See the NSFW screen caps after the jump!
(Thanks to CB and Casperfan!)
Click Image to Enlarge: 
i like how the other actors didn’t even LOOK at him coming in
He sure has growed all up since being the little kid that Janet plays with at the zoo in the opening theme to Three’s Company
I liked the show, can sure tell that is his son, buns are ok.