Gronk is denying a report from TMZ Sports that he partied with Flo Rida at the Foxwoods nightclub "Shrine"....racking up a $100,000 bar bill.

The bill posted on TMZ included 160 bottles of champagne, among various other alcoholic and non-alcoholic beverages. A PR Rep at Foxwoods claims that the receipt used by TMZ Sports for this story is legit.

However, Gronk offered a denial of sorts...warning his fans not to believe everything they read.