12:35 PM PT -- Shaun has issued a statement vigorously denying the allegations.
The female drummer in Shaun White's rock band is doubling down in her lawsuit against the X Games star -- claiming he sexually harassed her for years ... and she has the text messages to prove it.
We broke the story ... White is being sued by Lena Zawaideh -- who formed the band Bad Things with White back in 2008. She was fired shortly after the end of their 2014 tour. She claims she hasn't been paid for some of her work.
In new court docs obtained by TMZ Sports, Zawaideh claims she was subjected to the "darker, misogynistic personality" of White during her 7 years in the band.
Among the allegations, Zawaideh claims White sent her sexually explicit and graphic images of "engorged and erect penises" and forced her to watch sexually disturbing videos "including videos sexualizing human fecal matter."
One of the videos Zawaideh claims she was forced to watch was a couple killing a bear and then having sex on top of it.
She also claims White forced her to watch "Church of Fudge" -- a hardcore porn "involving a priest, a nun and fecal matter."
At one point, Zawaideh claims White stuck his hands down his pants, approached Zawaideh, and then "stuck his hands in her face trying to make her smell them."
She also claims he tried to kiss her on the mouth at a Halloween party in 2010 -- but she shut him down.
In her suit, filed by attorney Lawrance Bohm, Zawaideh claims White ran the band like a tyrant -- ordering her to cut her hair and wear sexually provocative outfits, despite her protests.
Zawaideh claims White would scold her when she wore more conservative outfits such as fleece sweaters.
Zawaideh issued a statement saying, "I am pursuing this case because women should not have to tolerate harassment at work. Shaun White should not be allowed to do whatever he wants just because he is famous. Although I am embarrassed to have been treated this way, I cannot sit by and watch him do this to other women."
Zawaideh is suing for non-payment of her contract plus other damages for the alleged sexual harassment.
We reached out to Shaun's camp -- so far, no word back.