'Ultimate Fighter' Star -- Suffers GRUESOME Penis Injury in Sex Accident

**WARNING -- YOU CANNOT UNREAD THIS STORY ... AND IT'S GOING TO MAKE YOU CRINGE **

... ESPECIALLY IF YOU ARE A MAN.

... OK, LAST WARNING

... SERIOUSLY, THIS IS MESSED UP.

OK, HERE WE GO ...

MMA fighter Ray Elbe -- who competed on "Ultimate Fighter 9" -- had to be rushed to a hospital in Malaysia earlier this month and required 10 stitches ... after he BROKE HIS PENIS during sex.

Elbe told the whole story -- in painfully graphic detail -- on an MMA website ... explaining how he was having sex with his GF, who was "on top" ... when she bounced a little too high, and crunched Ray's erect penis.

According to Ray, his penis "fractured" ... and "blood was everywhere." Ray says he immediately passed out from the pain.

Ray says he was rushed to a nearby hospital ... and underwent emergency surgery to close the wound and repair a "slight tear" in his urinary tube.

Elbe says the pain was so severe after the surgery, his johnson was "throbbing with each heart beat."

Elbe says he expects to make a full recovery -- and was ordered to take "anti-erection pills" for two weeks.

The fighter says he learned a hard lesson from the experience -- and will never let his GF be "on top" ever again.