'Bachelor Pad' Reject My Co-Star PUNCHED Me In the Face!

9/10/2011 6:45 AM PDT

'Bachelor Pad' Reject -- My Co-Star PUNCHED Me In the Face!

The bad blood between cast members on "Bachelor Pad" has spilled into real life ... so says one of the losers who claims Graham Bunn punched him in the face at a nightclub this week.

TMZ spoke with Justin Rego (aka Rated-R) -- who was eliminated from the reality show last month ... who says he was hanging out at the wrap party at a Hollywood nightclub Wednesday night when all hell broke loose.

According to Rego, two other members of the show -- Graham Bunn and Blake Julian -- had gotten into an argument ... and it started to become physical.

Rego says he went to break up the fight -- when Graham punched him in the nose ... and he started to bleed. Sources at the club tell us security rushed over to the scene and escorted Graham out of the building.

Justin tells us he does not plan on pressing charges -- but says he's still pretty pissed off at Graham. A rep for Graham tells TMZ, "It was nothing -- just boys being boys.”