Shaq -- I'm NEVER Going Back to Rap Again ... Like Never Ever

If you loved Shaquille O'Neal's "Kobe, Tell Me How My Ass Tastes" -- don't lose your copy, 'cause there will NEVER be a follow-up track ... according to Shaq himself.

We got the Diesel in NYC and told him about Russell Simmons' high praise. The Def Jam co-founder recently told TMZ Sports he wished he'd signed Shaq back in his heyday. We were hoping the news might coax him out of lyrical retirement.