The Situation just fired a warning shot across the bow of his loud-mouthed dad -- in the form of an email announcing Sitch's intent to sue pops ... ASAP!!!
Sources connected to la famiglia ... tell TMZ the Situation's lawyer sent the email to Frank Sorrentino -- aka The Confrontation -- warning of a lawsuit and an emergency injuction to shut down that website where Dad blasts Sitch.
Frank's rep says they're not taking down the website -- and they're not threatened -- especially since, he claims, the email referred to a "law suit."
Spelling counts ... even for a grown-ass man who calls himself The Confrontation.