And it all came to boiling point this weekend, at the New York Harper's Bazaar Icons party.
Cardi was escorted outside of the party, after trying to attack Nicki by throwing her shoe at her head. While being escorted out, you can see a major bump on Cardi's forehead.
A video on The Shade Room shows Cardi being held back as she was escorted out.
Later, Cardi posted on Instagram where she explained that she has "let a lot of sh*t slide!"
"I let you sneak diss me, I let you lie on me, I let you attempt to stop my bags, f*ck up the way I eat! You’ve threaten other artists in the industry, told them if they work with me you’ll stop f*ckin with them!!"
She added: "I addressed you once in person, I addressed you a second time in person, and every time you copped the plea!"
A witness spoke to The Associated Press saying that Nicki was talking to somebody when Cardi tried to attack her, but security were quick to intervene.
Obviously, Twitter was SO here for it: