If the age difference between you son and daughter is less than 3 years (2 in case of penetration) and both are under 14 years of age, we are in the presence of inappropriate exploratory sexual behaviours and when they appear, it is highly likely to be the tip of the iceberg and the child who proposes or compels the game or conduct is a former victim of abuse. It is expected that young children want to look at the body of others, but it is not expected that the exploration reaches the contact of the mouth of one with the genitals of another, it is expected that preschoolers kiss each other, even on the mouth (it is not recommended but it happens) but it is not expected that they kiss with their mouths open or with their tongues.  If inappropriate exploratory sexual behaviours appear, parents and educators must be attentive to them and know that it is a pretty sure indication that in some part of the domino a perpetrator will appear who has initiated some of the children involved and this replicates what has been learned. Therefore, it is very important to know how to recognize this type of behaviour and to know the protection and intervention protocols that we must offer to minors.