Dan Bilzerian Sued -- Roof-Tossed Porn Star Janice Griffith ... He Should've Known I Can't Fly

It's officially open season on Instagram playboy Dan Bilzerian -- he's been hit with his 2nd lawsuit in a week ... this time from the porn star he tossed off a roof and into a pool.

Janice Griffith just filed the suit against Bilzerian and Hustler magazine for the stunt she says left her with a broken foot. In her suit, Janice says Huster hired her to do a photoshoot at Dan's home back in April ... which would show off his "extravagant lifestyle."

She says the porn star-pool toss was suggested by Bilzerian and Hustler -- and she was assured it would be safe. She says they should've known she didn't have the skills to pull off the stunt ... based on her "experiences and qualifications." Translation: porn stars can't fly, dummy.

According to the suit, after the stunt went awry ... she was offered booze to ease her pain. She doesn't say if she accepted.

Afterward, Janice says she reached out to Bilzerian and his attorney -- and got back a letter from them she calls "unprofessional." Gotta say ... It was a pretty epic retort.

Bilzerian got sued last week by a chick he kicked in LIV Nightclub in Miami.

Janice is suing for unspecified damages and lost wages. Apparently the broken-foot-fetish market isn't booming.