Water Child (1995)

The two main characters engage in a somewhat sexual scene. The 12-year-old girl (which is played by a 14-year-old actress) and the 20-year-old 'mentally challenged' male character (played by a 29-year-old actor) are together in the kitchen after together having washed his hair. The girl initially kisses the male character's face in a 'playful' and non-sexual manner, but then becomes serious and kisses him once (passionately) on the mouth.

At another point in the movie the girl muses (while writing in her journal) whether 'she will ever become a woman' given their situation of being stranded for such a long time on an island in the middle of the ocean. The scene can be a bit uncomfortable to watch, especially given that the male character has the mental capacity of a 5-year-old. The forced nature of the scene is also troubling. Nothing happens further between these characters.