How often do you guys screw around during an operation?

Not a scrub but used to do spd and shadowed a knee replacement. During which the two scrubs were playfully throwing bits of knee cartilage at each other, I don't really see the harm and as gross as I found it, it was kinda funny and I can understand being desensitized to that kind of stuff. Was that something relatively normal or are things more serious in the OR?