slip of the tongue (noun)

1. During their romantic dinner, he accidentally mixed up her name with his ex-girlfriend's - a slip of the tongue that created an awkward moment.

2. In the anime series, the protagonist often uses a slip of the tongue to inadvertently reveal their secret identity to their friends.

3. The wizard's spell went wrong, causing a slip of the tongue that turned the brave knight into a talking frog.

4. In the movie blooper reel, the actor repeatedly had slips of the tongue while delivering their lines, creating hilarious outtakes.