This is probably a joke but I'll answer anyway
By 'cheeks' they mean buttocks so by "making them clap" is referring to them being so big/thick that they clap or make noise when you walk or move around or something.
I probably got played lol but whatever
Method acting is when an actor completely immerses themselves in their role. They, in a sense, become their character. An actor may use method acting to really pull of their character and make it feel as realistic as possible
