HIV-Positive Porn Star -- XXX Actress Wasn't at Risk ... 'Cuz We Didn't Have Sex!!!

The HIV-positive former male porn star known as "Buttman" couldn't possibly have put a female XXX actress at risk -- because he never had sex with her ... so claims his porn company.

TMZ broke the story ... porn star Katie Summers has filed a lawsuit against Buttman (real name John Stagliano) as well as his company, Evil Angel Productions, claiming Stagliano never disclosed he was HIV-positive before co-starring with her in sexual scenes.

Summers says she performed alongside Stagliano in "Buttman's Stretch Class #4" back in 2007, and the role involved sexual interaction.

But a rep for Evil Angel Productions has posted Katie's scene from the movie online ... and it doesn't show ANY penetration.

The scene features touching for sure ... but no genital-to-genital contact. As far as we know, you can't get HIV from what's depicted in the flick. The rep says, "It's the equivalent of shaking hands."

In the interest of full disclosure ... Evil Angel posted the entire scene on their website.