Here's how to give your toddler age-appropriate answers about sex and deal with natural (though sometimes blush-inducing) behaviors. Many toddlers express their natural sexual curiosity through self-stimulation. Boys may pull at their penises, and girls may rub their genitals. Teach your child that masturbation is a normal — but private — activity. If your child starts masturbating in public, try to distract him or her.