Michelle 'Bombshell' McGee -- Sex Tape Surfaces -- Rub-A-Dub-Dub, Baby

Jesse James' former mistress Michelle "Bombshell" McGee got down and dirty with 2 tatted-out sex freaks this year -- and the private XXX liaisons were all caught on tape ... tape that now lies in the hands of a giant porn company.

Sources tell TMZ, the footage documents two separate sexual encounters -- one with a tatted-up man ... and one with a tatted-up woman (above) ... both shot within the last year.

It's unclear how, but we're told the tapes were acquired by porn giant Red Light District -- the same adult studio that released the infamous "1 Night in Paris" -- and it plans to release the footage early next year in a 2-DVD box set.

And there's this -- we're told there's even more Bombshell sex footage floating around, but it's so extreme ... RLD is considering not releasing it for legal reasons.