Nicki Minaj -- Safaree Cheated on Me ... And Now I Love Meek Mill

Nicki Minaj was a loving and loyal girlfriend to ex Safaree Samuels until he went and cheated on her ... according to Nicki herself.

In response to Safaree's new and bitter song all about his relationship with Minaj, the "Pink Friday" rapper let a few things off her chest ... tweeting, "Lesson: don't cheat on a loyal woman. God will punish u. When he does, tell people the truth. The truth may set u free. Love. Always."

Minaj deleted that tweet, along with several others, but made sure not to take down the one that probably will hurt Safaree the most: "And just for the record, I'm in love with meek."

Simple, but effective.