Is fondling children in a way that leads to the emission of clear droplets nullifying of ablution and forbidden?

The fundamental principle is the permissibility of kissing children out of affection, compassion, and mercy. In fact, it may even be commendable, as stated in the Hadith (definition): "He who does not show mercy will not be shown mercy."

However, if the kissing is for pleasure, it is impermissible, even with mahrams (unmarriageable kin), because deriving pleasure from mahrams is forbidden. So, if a person finds pleasure in kissing, they must refrain from it.

The clear liquid that exits upon experiencing pleasure is madhy (pre-seminal fluid). It is impure (najis) and nullifies wudu (ablution). It must be washed off if it touches the body or clothing, but it does not necessitate ghusl (definition) (the major ritual bath).