Big Sean Denies Ab Surgery, Etching of Any Kind

Big Sean felt compelled to chime in after his six-pack abs became subject to internet debate ... his washboard stomach may have increased its load, but he's denying medical magic had anything to do with it!!!

The Detroit rap star reacted to a nutritionist influencer's accusations he had been taking steroids, which resulted in the well-sculpted gut he's sporting -- accusations that have been ripping through hip hop for a few years now.

Sean Don has picture proof that he was cut up before the social media era, but his counterparts -- such as Drake and French Montana -- haven't been so lucky with the internet's judgement.

Drake posted his own shirtless selfie last week and hasn't responded to the naysayers ... but there's plenty of them out there.