Porn Star Sues BangBros -- Suffering Syphilis Scare

Porn star Lylith Lavey says she was exposed to a syphilis-riddled penis during a shoot ... and she's blaming an adult video company.

Lavey -- real name Heather DeAngelo -- is suing porn producer BangBros ... claiming the company should have known porn actor Mr. Marcus was infected with the STD when she shot an oral sex scene in 2012.

In her lawsuit Lavey says she did NOT contract syphilis ... but suffered emotional distress and was shunned by other porn stars ... after Marcus' infection became industry gossip.