the girls are fighting

"The girls are fighting" is a meme-style commentary on any minor public squabble, especially among celebrities, brands, or even men. Not literally about girls. Used by all genders as ironic peanut-gallery commentary. Not concerning, just internet humour. If your kid uses it constantly, ask them where they first heard it, not to police their speech but to understand which online community they are in.

The girls are fighting is an internet idiom used as ironic commentary when two parties (often men, companies, or institutions) are bickering publicly. Use in social-media posts and casual conversation. Formal equivalent: "there is a petty public dispute." Common non-native mistake: taking it literally. "The girls" in this construction is gender-neutral and gently camp, often applied to corporate or political feuds for comic effect.