The shouting match went down Friday at the high-end clothing store Maxfield in West Hollywood, where somehow ... Meek happened to stumble across his old flame and her current partner. It's unclear who was there first, but regardless ... it got heated.
TMZ got a hold of the face-off, and you can see Meek in white being held back and escorted out of the store by both his own security team and guys working for the boutique. In the background, you clearly hear Nicki and Ken's voices ... they're pretty distinctive.
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No official word on what started the beef, but based on what we can make out ... it sounds like they were talking crap to each other over Nicki -- plain and simple. Oh, and get this ... sources tell us NM and KP were alone, and Meek was rolling with 10 heads deep.