It's no big deal. It didn't look as funny when Rafa was really cramping hehe but in hindsight I don't think Rafa would mind. Caro got buzz from pranking Djoker and I'm thinking this was done at Rafa's expense.
It was all in good fun. I think Rafa knows that his cramping was funny too. I just wish Caro would have really played it up and imitated it all the way through.