Justin and a friend arrived at a party on Saturday night that was being hosted by Patrick Schwarzenegger. Sources tell TMZ that Justin was talking with some people when a guy walked in, spotted a woman in the group and became angry. TMZ says the man appeared to be on drugs and that the woman may have been the man's ex-girlfriend.
The man approached the woman, and grabbed her by the throat and wouldn't release her. Bieber and his friend screamed at the man to let of the woman, but reportedly screamed back, "Go f*** yourself," while still choking the woman.
That's when Bieber acted, hitting the man in the face, and pushing him up against the wall, helping the woman break free.
The man was thrown out of the party and was eventually arrested after chasing an SUV he believed to contain the pop star, and was screaming Beiber's name when he hit allegedly the vehicle.
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