1. His childish behavior at the meeting was embarrassing for everyone involved.
2. Stop being so childish and take responsibility for your actions.
3. She couldn't stand his constant teasing and childish pranks.
4. The argument between the siblings quickly escalated into childish name-calling.
5. I can't believe he still throws tantrums like a childish brat.
6. Her childish giggling during the serious presentation was unprofessional.
7. It's time to grow up and stop acting so childish all the time.
8. His immature and childish behavior made it difficult to take him seriously.
9. The childish graffiti on the walls of the school needed to be cleaned up.
10. She found his obsession with video games to be childish and unproductive.