Joe Jonas -- THERE IS NO SEX TAPE

Sorry you creepy weirdos ... Joe Jonas did NOT record a raunchy sex tape with his Swiss model GF ... despite reports to the contrary ... Joe's rep tells TMZ.

Reports have been circulating that Joe -- who once wore a purity ring espousing his virginity -- filmed himself doing the nasty with gf Blanda Eggenschwiler while under the influence of pot and alcohol. The reports claim the sex footage features some crazy BDSM stuff, including paddles and ball gags.

But Joe's rep tells TMZ, it's total BS ... no such tape exists.