The three-way kiss scene between Zendaya, Mike Faist, and Josh O'Connor in 'Challengers' was not in the original script.The scene was added during rehearsals to develop the love triangle between the characters.Director Luca Guadagnino and screenwriter Justin Kuritzkes worked on enhancing the scene's usefulness and fun.The trio of actors, Zendaya, Faist, and O'Connor, underwent intense training to portray tennis stars in the film.