Ariana Grande is being sued over one of her BIGGEST songs

This dude reckons Ari copied him.

By Sammy Stewart

This dude reckons Ariana Grande totally ripped off his song and has decided to sue her.

Songwriter Alex Greggs reckons Ari copied the tune in his 2010 track titled Takes All Night and used it for her BOP One Last Time.

E! News has obtained documents whereby Alex alleges that "Takes All Night bear similarities so striking that it is highly likely the works were not created independently of one another."

The lawsuit also states: "Although the rhythm of the two compositions may differ to accommodate the prosody of the lyrics, there is substantial similarity on the most important rhythmic placement of the pitches on strong melodic and harmonic beats."

David Guetta (who wrote One Last Time), Rami Yacoub, Carl Falk, and a bunch of others have also been dragged in the drama and Alex is reportedly seeking $150,000 per infringement.

Hmm, take a listen to Alex's tune HERE and Ariana's HERE and we'll let you be the judge.