Flavor Flav -- Accused Of Double-Knife Rampage Before Arrest

Flavor Flav violently threw his fiancee to the ground last night, ripped out her earring, then chased her teenage son around the house while clutching TWO KNIVES -- this according to the police report from the rapper's domestic dispute yesterday.

According to the Vegas police report, the argument between the rapper and his 39-year-old fiancee started over accusations Flav had cheated on her -- and quickly turned violent, with Flav grabbing his fiancee and throwing her to the ground twice.

According to the report, Flav's fiancee claims her earring was ripped out during the altercation ... and her 17-year-old son jumped in to defend her.

At that point, the report continues, Flav grabbed two knives and chased her son around the house -- eventually kicking down a locked door to get to him. Flav then allegedly threatened to kill him.

According to the report, Flav denied chasing the teenager with the knives. He also denied the whole death threat thing.

TMZ broke the story ... Flav was arrested for domestic violence early yesterday morning and subsequently booked on two charges -- misdemeanor battery (for allegedly attacking his fiancee) and felony assault with a deadly weapon (for the knife thing).