Eminem - Guilty Conscience - [1999]

"The song 'Guilty Conscience' [video | lyrics] has gotten such rotten responses"* even Eminem knows this song is thought to be pretty fucked up from a content perspective, but it's actually pretty tame compared to this blatant reference to a pretty nasty event, even for an ex-NWA member, delivered via the biggest punch line in the song.  This exchange form the last verse covers it:

 [Eminem]

Okay, Thought about it, still wanna stab her?
Grab her by the throat, get your daughter and kidnap her?
That's what I did, be smart, don't be a retard
You gonna take advice from somebody who slapped Dee Barnes?

[Dr. Dre]
What'chu say? 

 [Eminem]
What's wrong? Didn't think I'd remember?

[Dr. Dre]

  I'ma kill you motherfucker!

[Eminem]
Uhhh-aahh! Temper, temper!

Apparently Dre didn't approve of how the group was portrayed in Barnes' interview with Ice Cube about why he left NWA in 1990. So when he ran into her at a party and had this to say about their encounter:
"People talk all this shit, but you know, somebody fuck with me, I'm gonna fuck with them. I just did it, you know. Ain't nothing you can do now by talking about it. Besides, it ain't no big thing-- I just threw her through a door." 

Others say it was worse than just that and she eventually sued for an insane amount which was settled by Dre out of court.  Would have loved to have seen the look on Dre's face when Em came up with those lyrics.

[*]From"Whatever You Say I Am" on the Marshall Mathers LP