In order to prevent the actors from having a "physiological reaction" during the filming of a kiss scene, directors usually communicate with the actors in advance to inform them of how to deal with the situation. In addition, some directors will also set up air conditioning or cold water sprays on the set to reduce the tension level of the actors and reduce the possibility of embarrassing situations.
In addition to this, some directors will take more stringent measures, such as increasing the number of on-set crews to ensure that the actors can concentrate on filming without outside distractions. Some directors will even require the actors to undergo special training to improve their professionalism and self-control.
However, despite all the precautions taken by the directors, it is still not possible to completely avoid the "physiological reaction" of the actors while filming the kiss scene. Faced with this situation, directors usually resort to compromises, such as pausing the shoot to give the actors some time to calm down, or adjusting the angles and shots of the shoot to avoid awkward situations. Sometimes, the director will even rearrange the shooting plan and schedule the filming of the kiss scene at the end to avoid unnecessary trouble.
In general, it is not uncommon for actors to have an embarrassing situation of "physiological reaction" during the filming of kiss scenes, but through the careful arrangement and handling of the directors, it can usually be resolved satisfactorily without causing much impact on the entire filming process. At the same time, directors also need to have a certain sensitivity and processing ability to deal with various unexpected situations and ensure the smooth progress of the shooting.