Nick Young: Gilbert Arenas Makes Tasteless Joke ... I'll Take Out Your Baby Mama

Nick Young got a visit from his buddy Gilbert Arenas, who was ready to celebrate Nick's new single life -- but also cracked an O.J. Simpson joke about killing Nick's baby mama, Keonna Green.

Ex-NBA star Gilbert took a tour of Nick's crib and recorded the whole thing -- showing a mostly empty house while yelling Iggy Azalea "took it all!" He also painted over Iggy's name on a wall.

But watch the video, it's a lot of laughs ... until Gilbert says, "I heard you got a problem with your baby mom's. You know I'm the new O.J." -- and then flashes what looks like a knife.

Insanity.