Kanye West allegedly assaulted an 18-year-old man over vulgar name-calling towards fiancee Kim Kardashian. Credit: Michael Buckner/WireImage

Kanye West allegedly got into an altercation with an 18-year-old man on Monday, Jan. 13. The 36-year-old rapper reportedly punched the man in the arm over racial slurs he made towards fiancee Kim Kardashian.

A source close to Kardashian tells Us Weekly that the incident occurred at a Beverly Hills building where the couple was visiting to attend a furniture meeting for their new home. The young man allegedly shouted derogatory remarks towards nearby paparazzi. When Kardashian walked by, she reportedly told him, "You really shouldn't use racial slurs like that." He then allegedly began directing offensive comments at Kardashian, 33, and called her a "n****r lover."

West reportedly then came to Kardashian's aid. He allegedly followed the man into a chiropractor's office, and punched him in the arm. Police were then called.

The source close to Kardashian tells Us that she was "terrified."